Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 Computer Systems October/November 2023
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2023 series for most
Cambridge IGCSE, Cambridge International A and AS Level components, and some Cambridge O Level
components.

This document consists of 10 printed pages.

© UCLES 2023 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme October/November 2023
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond
the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

Mark scheme abbreviations

/ separates alternative words / phrases within a marking point

// separates alternative answers within a marking point
underline actual word given must be used by candidate (grammatical variants accepted)
max indicates the maximum number of marks that can be awarded
( ) the word / phrase in brackets is not required, but sets the context

Note: No marks are awarded for using brand names of software packages or hardware.

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Question Answer Marks

1(a) − A 1

1(b) − C 1

1(c) − Control unit 1

1(d) Any two from: 2

− (The CPU completes) 2.4 billion
− … cycles/clock pulses per second

1(e)(i) Any two from: 2

− Stores data …
− … that has been fetched/to be written to memory

1(e)(ii) Any three from: 3

− Memory address register // MAR
− Program counter // PC
− Current instruction register // CIR
− Accumulator // ACC

Question Answer Marks

2(a) One mark for each correct part of the fee, in the correct order: 2
− 17
− 70
(Correct fee $17.70)

2(b) One mark for each correct binary value: 2

Register 1
− 00001110
Register 2
− 01100010

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Question Answer Marks

2(c) One mark for each correct hexadecimal value, in the correct order. 4

− A
− 0
− 3
− D
(Ticket number A03D)

2(d) Two from: 2

− It contains logic gates/switches …
− … that process the values 1 and 0 // have two states

2(e) Any four from: 4

− Compares the ticket number received to stored data
− … that is a database/file of ticket numbers
− … checks the ticket number is listed as paid
− If the data matches/cost is paid it sends a signal to raise the barrier
− If the data does not match/cost is not paid, the barrier remains down

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Question Answer Marks

3 One mark for each correct term: 4

Term Description

hardware A collective term for the physical

components of the computer system.

application software A type of software that provides

services that the user requires and
allows the user to perform tasks on the
computer.

operating system A type of software that manages the

main functions of the computer,
including managing files and managing
memory.

firmware A type of software that is stored in the

read only memory (ROM). It includes
the basic input output system (BIOS)
and the bootloader.

Question Answer Marks

4(a) One mark for each correct transmission method: 2

− Serial half-duplex
− Serial full-duplex

4(b) Any four from: 4

− The number of 1 s/0 s are counted
− A parity bit is added to each byte/7 bits before transmission
− … to make the sum of the bits/1 or 0 s in each byte odd
− After transmission, if the number is odd no error is detected
− After transmission, if the number is even an error is detected
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Question Answer Marks

4(c) – Echo (check) 1

Question Answer Marks

5(a) Any five from: 5

− (The analogue sound is) recorded using a microphone
− The sound wave is sampled
− … measuring the height/amplitude
− Each amplitude has a unique binary value
− The sample rate is set
− … that is the number of samples taken per second
− The sample resolution is set
− … that is the number of bits used for each sample
− Each sample taken is converted to binary

5(b) Two from: 2

− Increase the sample rate
− Increase the sample resolution

5(c) Any three from: 3

− They want to be able to edit the original sound file
− They want the highest sound quality for the file // They want the sound to be closest to the original recording
− … using lossy would reduce the sound quality
− … using lossy will permanently remove some of the data // no data will be permanently removed with lossless

5(d) Any four from (MAX 3 for ASCII/Unicode alone): 4

− ASCII has limited/fewer characters // Unicode has a more characters
− ASCII covers a limited set of languages/fewer languages
− Unicode includes many/more languages/emojis
− ASCII requires 7/8 bits per character
− Unicode requires up to 16/32 bits per character
− ASCII has 128/256 characters
− Unicode has 65 536/4 294 967 296 characters // approx. 60/70 thousand/4 billion characters

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Question Answer Marks

6 The diagram includes (any four from): 4

− Traffic passing both ways through the firewall
− An indication that criteria is set for the firewall
− Traffic is compared to criteria
− Traffic being rejected if it does/does not meet criteria
− Traffic being accepted if it does/does not meet criteria
e.g.

Question Answer Marks

7 One mark for each correct term, in the correct order: 4

− header
− destination address
− routers
− last

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Question Answer Marks

8(a) Any two from: 2

− Data is stored on platters
− (Platters) are divided into tracks and sectors
− Has components that are spun
− Data is read/written using a read/write arm
− Data is read/written using electromagnets
− Magnetic field determines the binary value
− It is non-volatile

8(b) Any three from: 3

− Flashes data onto chips
− Uses transistors
− Uses NAND/NOR technology
− Uses control gates
− Uses flow gates
− Controls the flow of electrons
− It can be volatile or non-volatile

8(c) One mark for an example in each storage type e.g.: 3

Magnetic
− HDD
− Magnetic tape
− Floppy disk
− Magnetic strip
Solid state
− SSD
− USB drive
− SD card
− RAM
Optical
− CD
− DVD
− Blu-ray

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Question Answer Marks

9(a) Any one from: 1

− Operating system // Interrupt handler

9(b) Any five from: 5

e.g.
− Key press generates the interrupt
− Interrupt given a priority
− Interrupt is sent to CPU
− Interrupt is placed in a queue
− CPU stops current task to check the queue/service the interrupt …
− … using an interrupt service routine
− If key press is highest priority the interrupt is processed

9(c)(i) Any two suitable hardware example e.g.: 2

− Moving the mouse
− Clicking a mouse button
− Plugging in a device
− Paper jam in printer
− Printer out of paper

9(c)(ii) Any two suitable software examples e.g.: 2

− Division by zero
− Two processes accessing the same memory location
− Null value

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 Algorithms, Programming and Logic October/November 2023
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2023 series for most
Cambridge IGCSE, Cambridge International A and AS Level components, and some Cambridge O Level
components.

This document consists of 13 printed pages.

© UCLES 2023 [Turn over

0478/21 Cambridge IGCSE – Mark Scheme October/November 2023
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond
the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

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Question Answer Marks

1 C 1

Question Answer Marks

2 B 1

Question Answer Marks

3 One mark for each correct line from description to data type 4

Description Data type

BOOLEAN
a whole number

CHAR

a single letter

INTEGER

a word or phrase REAL

a number with two decimal STRING

places

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Question Answer Marks

4 One mark for each correct word 3

• array
• constant
• variable

Question Answer Marks

5(a) One mark for each point (max two) 2

• simplifying the problem
• removing unnecessary details from the problem // selecting elements required
• filtering out irrelevant characteristics from those elements

5(b) One mark for each point (max three) 3

• inputs
• processes
• outputs
• storage

5(c) One mark for stage, one mark for matching description (max two) 2
• design (1) details of solution set out (1)
• coding (1) program is developed (1)
• testing (1) program is tested for errors (1)

Question Answer Marks

6(a) Displaying/sort 10 names in alphabetical order 9 1

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Question Answer Marks

6(b) One mark for each point (max four) 4

• Initialisation
• inputting 10 names
• storing the names in an array
• sorting the names in alphabetical order using a bubble sort
• displaying the 10 names
• iteration

6(c) One mark for a meaningful identifier for the array 3

A Names // ArrayNames

Two marks for 3 meaningful identifiers for variables

One marks for 1 or 2 meaningful identifiers for variables
T Temp
C Counter
L Length

6(d) One mark for each point (max two) 2

• use of comments
• use of procedures/functions
• use of white space

Question Answer Marks

7(a) One mark for each point 4

• NOT A
• AND B
• OR NOT C
• expression correct (NOT A AND B) OR NOT C

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Question Answer Marks

7(b) 4
A B C X

0 0 0 1

0 0 1 0

0 1 0 1

0 1 1 1

1 0 0 1

1 0 1 0

1 1 0 1

1 1 1 0

4 marks for 8 correct outputs

3 marks for 6/7 correct outputs
2 marks for 4/5 correct outputs
1 mark for 2/3 correct outputs

Question Answer Marks

8(a) Range check 1

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Question Answer Marks

8(b) One mark for each of the following points 6

START
• correct use of flowchart symbols
• working flow lines and complete
INPUT Length • both inputs correct
• working range check
• working calculation
• correct output rounded to two decimal places
Is Length >=0.5 No
AND Length <=
6.0 ?

Yes

INPUT Cost

Price  Length * Cost

OUTPUT
"Price ",
ROUND(Price,2)

STOP

8(c) One mark for set of test data, one mark for purpose (max four) 4

Example:
1 and 1 (1) normal data to ensure the algorithm accepts this test data (1)
–1 and 1 (1) abnormal data for length to ensure that it is rejected (1)

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Question Answer Marks

8(d) One mark for two correct headings 3

Two marks for three correct headings
Three marks for all headings correct and no other headings unless used in 8(b)

Length Cost Price OUTPUT

8(e) One mark for each point (max two) 2

• validate Cost …
• … with a range/presence check
• add another validation check for Length

Question Answer Marks

9(a) One mark for each appropriate field name and correct data type 5
CatNo text/alphanumeric
Description text/alphanumeric
StockLevel integer
Price real
Painted Boolean

9(b)(i) CatNo 1

9(b)(ii) Unique identifier 1

9(c) SELECT lists the fields to be displayed 3

FROM identifies the table
WHERE identifies the search criteria

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Question Answer Marks

10 • AO2 (maximum 9 marks) 15

• AO3 (maximum 6 marks)

Data Structures required names shown underlined must be used as given in the scenario
2D Array or list Evening[1:10, 1:20] / Evening[0:9, 0:19]
Variables Counter, SeatCounter, NumSeats, Row, Column

Requirements (techniques)
R1 Find number of seats available for each performance and output (searching, nested iteration, output)
R2 Inputs and validates number of seats (input, iteration, and selection)
R3 Checking if seats available (selection, assignment, output with appropriate messages)

Example 15-mark answer in pseudocode

// meaningful identifier names and appropriate data structures to store the data required
DECLARE Counter, SeatCounter, NumSeats, Row, Column : INTEGER

CONSTANT HouseFull = 200

CONSTANT MaxRow = 10
CONSTANT MaxColumn = 20

SeatCounter1  0 // initialise seat counter for performance 1

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Question Answer Marks

10 FOR Row  1 TO 10
FOR Column  1 TO 20
IF Evening[Row, Column]
THEN
SeatCounter  SeatCounter + 1
ENDIF
NEXT Column
NEXT Row

// validate input
OUTPUT "How many seats do you want to book? 1, 2, 3 or 4 "
INPUT NumSeats

WHILE 1 < NumSeats OR NumSeats > 4 OR NumSeats <> ROUND(NumSeats, 0)

OUTPUT "Please enter 1, 2, 3 or 4 for the number of seats "
INPUT NumSeats
ENDWHILE

IF SeatCounter + NumSeats > 200)// check for house full

THEN
OUTPUT "House full"
ELSE
IF SeatCounter + NumSeats > 200 // checks for not enough seats
THEN
OUTPUT "Only ", SeatCounter + NumSeats – 200, " seats left"
ELSE
FOR Counter  1 TO NumSeats // book required number of seats for performance
Evening[MOD(SeatCounter + Counter, MaxColumn), DIV(SeatCounter +
Counter), MaxColumn]  TRUE
OUTPUT "Row ", MOD(SeatCounter + Counter, MaxColumn), " seat ",
DIV(SeatCounter + Counter, MaxColumn)," booked"
NEXT Counter
ENDIF

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Marking Instructions in italics

AO2: Apply knowledge and understanding of the principles and concepts of computer science to a given context,
including the analysis and design of computational or programming problems

0 1-3 4-6 7-9

No creditable At least one programming Some programming techniques used The range of programming techniques
response. technique has been used. are appropriate to the problem. used is appropriate to the problem.
Any use of selection, iteration, More than one technique seen All criteria stated for the scenario have
counting, totalling, input and applied to the scenario, check the list been covered by the use of
output. of techniques needed. appropriate programming techniques,
check list of techniques needed.

Some data has been stored but Some of the data structures chosen The data structures chosen are
not appropriately. are appropriate and store some of the appropriate and store all the data
Any use of variables or arrays or data required. required.
other language dependent data More than one data structure used to The data structures used store all the
structures e.g. Python lists. store data required by the scenario. data required by the scenario.

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Marking Instructions in italics

AO3: Provide solutions to problems by:

evaluating computer systems making reasoned judgements presenting conclusions

0 1-2 3-4 5-6

No creditable Program seen without relevant Program seen with some relevant The program has been fully
response. comments. comment(s). commented

Some identifier names used are The majority of identifiers used are Suitable identifiers with names
appropriate appropriately named. meaningful to their purpose have been
Some of the data structures Most of the data structures used have used throughout.
used have meaningful names. meaningful names. All of the data structures used have
meaningful names.

The solution is illogical. The solution contains parts that may The program is in a logical order.
be illogical.

The solution is inaccurate in The solution contains parts that are The solution is accurate.
many places. inaccurate. Solution logically performs all the
Solution contains few lines of Solution contains lines of code with tasks given in the scenario. Ignore
code with errors that attempt to some errors that logically perform minor syntax errors.
perform a task given in the tasks given in the scenario. Ignore
scenario. minor syntax errors.

The solution attempts at least The solution attempts to meet most of The solution meets all the
one of the requirements. the requirements. requirements given in the question.
Solution contains lines of code Solution contains lines of code that Solution performs all the tasks given in
that attempt at least one task perform most tasks given in the the scenario.
given in the scenario. scenario.

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 Computer Systems May/June 2023
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the May/June 2023 series for most
Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some
Cambridge O Level components.

This document consists of 10 printed pages.

© UCLES 2023 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme May/June 2023
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

 the specific content of the mark scheme or the generic level descriptors for the question
 the specific skills defined in the mark scheme or in the generic level descriptors for the question
 the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

 marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond
the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
 marks are awarded when candidates clearly demonstrate what they know and can do
 marks are not deducted for errors
 marks are not deducted for omissions
 answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

Mark scheme abbreviations

/ separates alternative words / phrases within a marking point

// separates alternative answers within a marking point
underline actual word given must be used by candidate (grammatical variants accepted)
max indicates the maximum number of marks that can be awarded
() the word / phrase in brackets is not required, but sets the context

Note: No marks are awarded for using brand names of software packages or hardware.

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Question Answer Marks

1(a)  B 1

1(b) One mark per each correct conversion 3

 00110010
 01100110
 11011101

1(c) One mark for full method of working e.g. conversion to binary then flipping and adding 1 2
One mark for correct answer

 10110010

1(d) One marks per each correct nibble 3

One mark for correct working in binary (showing 4 correct carries)

1 1 11
0 0 1 1 0 0 1 1
0 1 1 0 0 0 0 1

10 0 1 0100

1(e) Two from: 2

 The result of the calculation is greater than 255 // The value generated is larger than can be stored in the register
 The result of the calculation would require more than 8 bits to be represented // A register has a predetermined
number of bits and there are too many bits for it

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Question Answer Marks

2(a) One mark for each correct definition: 2

 The sample rate is the number of samples taken in a second/per time unit
 The sample resolution is the number of bits per sample

2(b)  Lossy compression 1

2(c)(i) Any two from: 2

e.g.
 Destination/receivers (IP) address
 Packet number
 Originator’s/senders (IP) address

2(c)(ii) Any five from: 5

 Data is broken/split/divided into packets
 Each packet (could) take a different route
 A router controls the route/path a packet takes
 … selecting the shortest/fastest available route/path
 Packets may arrive out of order
 Once the last packet has arrived, packets are reordered
 If a packet is missing/corrupted, it is requested again

Question Answer Marks

3(a) One mark for each correctly circled storage device: 3

 Compact disk (CD)
 Solid-state drive (SSD)
 Hard disk drive (HDD)

3(b)  C 1

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Question Answer Marks

4 One mark for each correct term in the correct place: 4

 System
 Application
 Operating
 Hardware

Question Answer Marks

5(a) Any one from: 1

 Level
 Pressure
 Moisture

5(b) Any Six from: 6

 Sensor continually sends digitised data to microprocessor
 Microprocessor compares data to stored value(s)
 If value is outside range / matches microprocessor sends signal to release water to refill water bowl
 … bowl filled by set amount // bowl filled for certain time
 Actuator used to release water
 Whole process repeats until turned off/stopped

Question Answer Marks

6(a)(i)  Network interface card/controller // NIC // WNIC 1

6(a)(ii)  Media access control/MAC address // MAC 1

6(b)(i)  Router 1

6(b)(ii) Three from: 3

 It can be used to uniquely identify a device (on a network)
 It can change …
 … each time the device is connected to the network

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Question Answer Marks

7(a) Any two from: 2

 Close to the language processed by computers
 May use mnemonics
 An example is assembly language/machine code

7(b) Any two from: 2

 Can directly manipulate the hardware
 No requirement for the program to be portable
 Program will be more memory efficient
 No requirement for a compiler/interpreter
 Quicker to execute
 Can use specialised hardware

Question Answer Marks

8(a) Three from: 3

 Trial and error to guess a password
 Combinations are repeatedly entered …
 … until correct password is found
 Can be carried out manually or automatically by software

8(b)(i) Any two from: 2

e.g.
 Steal/view/access data
 Delete data
 Change data
 Lock account // Encrypt data
 Damage reputation of a business

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Question Answer Marks

8(b)(ii) Any three from: 3

e.g.
 Virus
 Worm
 Trojan horse
 Spyware
 Adware
 Ransomware

8(c) Any two from: 2

 Two-step verification//Two-factor authentication//by example
 Biometrics
 Firewall // Proxy-server
 Strong/complex password // by example
 Setting a limit for login attempts
 Drop-down boxes
 Request for partial entry of password

Question Answer Marks

9(a) Any two from: 2

 It has a mechanical structure/framework
 It has electrical components // by example

9(b) Any two from: 2

e.g.
 Employees don’t need to lift heavy furniture
 Employees can be protected from dangerous tasks
 Employees can utilise their skills in other tasks
 Employees don’t need to perform repetitive/mundane tasks

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Question Answer Marks

9(c) Any one from: 1

e.g.
 Expensive to install/purchase/setup
 High ongoing costs/maintenance costs
 May deskill the workforce
 If they malfunction, production may stop

Question Answer Marks

10(a)  To obtain personal data/details // by example 1

10(b) One mark for each correct part of the diagram. 4

Diagram shows:
 User clicks/opens attachment/link that triggers download
 Malicious software downloaded onto user's computer
 User enters website address
 User is redirected to fake website

e.g.
User types in
web address
User
Real
computer
website
malware

Fake
Request website
gets
User clicks link that redirected
downloads malware
to computer

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Question Answer Marks

10(c) Two from: 2

Displays web pages
… by rendering HTML

10(d) Any three from: 3

e.g.
 Storing bookmarks/favourites
 Recording user history
 Allowing use of multiple tabs
 Providing navigation tools // by example
 Providing an address bar
 Managing protocols // by example // checking digital certificate
 Send URL to DNS
 Sends a request to the IP address/web server (to obtain the contents of a webpage)
 Runs active script/JavaScript/client-side script
 Allows files to be downloaded from website/internet

10(e) Any four from: 4

 Session cookies are stored in memory/RAM
 … whereas persistent cookies are stored on the hard drive/secondary storage
 When the browser is closed a session cookie is lost
 … whereas a persistent cookie is not lost
 … until deleted by the user/they expire

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 Algorithms, Programming and Logic May/June 2023
MARK SCHEME
Maximum Mark: 50

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the May/June 2023 series for most
Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some
Cambridge O Level components.

This document consists of 18 printed pages.

© UCLES 2023 [Turn over

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Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

 the specific content of the mark scheme or the generic level descriptors for the question
 the specific skills defined in the mark scheme or in the generic level descriptors for the question
 the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

 marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond
the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
 marks are awarded when candidates clearly demonstrate what they know and can do
 marks are not deducted for errors
 marks are not deducted for omissions
 answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

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Question Answer Marks

1(a) One mark for each correct line. 4

Program development life cycle description Program development life cycle stage

develop an algorithm to solve the analysis

problem using structure diagrams,
flowcharts or pseudocode

coding
detect and fix the errors in the
program
design

identify the problem and its

requirements
evaluation

write and implement the

instructions to solve the problem testing

1(b) One mark for naming or describing each component part, max three 3

For example:

inputs // what is put into the system

processes // actions taken to achieve a result
outputs // what is taken out of the system
storage // what needs to be kept for future use

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Question Answer Marks

2 A 1

Question Answer Marks

3(a) One mark per mark point, max two 2

 Validation is an automated check carried out by a computer

 … to make sure the data entered is sensible/acceptable/reasonable

3(b) One mark for each appropriate test data, max three 6
One mark for each correct accompanying reason, max three

For example:

Normal – 75
Reason – the data lies within the required range and should be accepted

Abnormal – Sixty
Reason – this is the wrong data type and should be rejected

Extreme – 200
Reason – the highest value in the required range that should be accepted

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Question Answer Marks

4 One mark per mark point, max four 4

DIV, max two

 To perform integer division
 Meaning only the whole number part of the answer is retained
 Example of DIV For example DIV(9,4) = 2

ROUND, max two

 To return a value rounded to a specified number of digits / decimal places
 The result will either be rounded to the next highest or the next lowest value
 … depending on whether the value of the preceding digit is >=5 or <5
 Example of ROUND for example, ROUND(4.56, 1) = 4.6

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Question Answer Marks

5(a) One mark per mark point, max four 4

 Line 04 / IF Number < 0

should be IF Number > 0

 Line 10 / Exit  1 // Line 01/ Exit  1 and Line 02 / WHILE Exit <> 0
should be Exit  0 // should be Exit  0 and WHILE Exit = 0

 Line 13 / ENDIF
should be ENDWHILE

 Line 14 / OUTPUT "The total value of your numbers is ", Number

should be OUTPUT "The total value of your numbers is ", Total

Correct algorithm:

01 Exit  1
02 WHILE Exit <> 0 DO
03 INPUT Number
04 IF Number > 0
05 THEN
06 Total  Total + Number
07 ELSE
08 IF Number = 0
09 THEN
10 Exit  0
11 ENDIF
12 ENDIF
13 ENDWHILE
14 OUTPUT "The total value of your numbers is ", Total

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Question Answer Marks

5(b) One mark per mark point, max four 4

 Initialise a new (counting) variable
 … Count  0 // to count the acceptable numbers
 Insert a counting statement between lines 05 and 07
 … Count  Count + 1
 Add a new output after the loop/after line 13 / at the end (of the program)
 … OUTPUT Count

Question Answer Marks

6 One mark for each correct feature, max two 4

One mark for each correct accompanying reason, max two

For example:

Meaningful identifiers – to enable the programmer (or future programmers) to easily recognize the purpose of a variable /
array / constant // to enable easy tracking of a variable / constant / array through the program

Use of comments – to annotate each section of a program so that a programmer can find specific sections / so that the
programmer knows the purpose of that section of code

Procedures and functions – to make programs modular and easier to update / add functionality

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Question Answer Marks

7(a) One mark per correct column, max four 4

Pointer Letter Choice OUTPUT

1 F

6 Letter F is represented by Foxtrot

Another Letter? (Y or N)

1 D

4 Letter D is represented by Delta

Another Letter? (Y or N)

7(b) (Linear) search 1

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Question Answer Marks

7(c) One mark per mark point, max two 2

 The algorithm would not stop

 … because it would not have found the item it was seeking

Or

 The array would run out of values after the pointer reached 13
 the algorithm will crash

Question Answer Marks

8(a) One mark per mark point, max three 3

 Storing string in Phrase
 Correct use of LENGTH function
 Correct use of UCASE function
 Correct outputs of LENGTH and UCASE

For example:

Phrase  "The beginning is the most important part"

OUTPUT LENGTH(Phrase)
OUTPUT UCASE(Phrase)

8(b) One mark for each correct line, max two 2

40
THE BEGINNING IS THE MOST IMPORTANT PART

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Question Answer Marks

9(a) One mark for each correct gate, with the correct input(s) as shown. 4

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Question Answer Marks

9(b) Four marks for eight correct outputs. 4

Three marks for six or seven correct outputs.
Two marks for four or five correct outputs.
One mark for two or three correct outputs

A B C Z

0 0 0 0

0 0 1 1

0 1 0 1

0 1 1 0

1 0 0 0

1 0 1 0

1 1 0 1

1 1 1 0

Question Answer Marks

10(a) One mark for the correct field name 2

One mark for the correct reason

For example:

TVCode
Each entry in this field is a unique identifier

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Question Answer Marks

10(b) Two marks for four correct answers. 2

One mark for two or three correct answers.

Field Data type

TVCode Text

ScreenSize Integer

SmartTV Boolean

Price$ Real

10(c) One mark for each correct answer 4

ScreenSize
Price$
FROM
YES

Correct code:

SELECT TVCode, ScreenSize, Price$

FROM TVRange
WHERE SmartTV = YES;

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Question Answer Marks

11 Read the whole answer: 15

Check if each requirement listed below has been met. Requirements may be met using a suitable built-in function from the
programming language used (Python, VB.NET or Java).
On place a SEEN mark if requirement met, cross if no attempt seen, omission mark and/or comment if partially met (see
marked scripts).

Use the tables for AO2 and AO3 below to award a mark in a suitable band using a best fit approach, then add up the total:
 AO2 (maximum 9 marks)
 AO3 (maximum 6 marks)

Data structures required:

The names underlined must match those given in the scenario:

Arrays or lists Days[], Readings[], AverageTemp[]

Variables WeekLoop, DayLoop, InTemp, TotalDayTemp, TotalWeekTemp, AverageWeekTemp

Requirements (techniques):
R1 Input and store hourly temperatures and validation of input temperatures for each day (with prompts, range check and
(nested)iteration)
R2 Calculate, round to one decimal place and store daily average temperatures and calculate the weekly average
temperature rounded to one decimal place (iteration, totalling and rounding)
R3 Convert all average temperatures to Fahrenheit (to one decimal place) and output the average temperatures in both
Celsius and Fahrenheit. Output with appropriate messages. (output and rounding)

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Question Answer Marks

11 Example 15 mark answer in pseudocode

// meaningful identifiers and appropriate data structures for

// all data required
DECLARE Days : ARRAY[1:7] OF STRING
DECLARE Readings : ARRAY[1:7, 1:24] OF REAL
DECLARE AverageTemp : ARRAY[1:7] OF REAL
DECLARE WeekLoop : INTEGER
DECLARE DayLoop : INTEGER
DECLARE InTemp : REAL
DECLARE TotalDayTemp : REAL
DECLARE TotalWeekTemp : REAL
DECLARE AverageWeekTemp : REAL
// initial population of Days[] array
// input and a loop are also acceptable
Days[1]  "Sunday"
Days[2]  "Monday"
Days[3]  "Tuesday"
Days[4]  "Wednesday"
Days[5]  "Thursday"
Days[6]  "Friday"
Days[7]  "Saturday"
// input temperatures inside nested loop
FOR WeekLoop  1 TO 7
TotalDayTemp  0
FOR DayLoop  1 TO 24
OUTPUT "Enter temperature ", DayLoop, " for ", Days[WeekLoop]

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Question Answer Marks

11 INPUT InTemp
// validation of input for between -20 and +50 inclusive
WHILE InTemp < -20.0 OR InTemp > 50.0 DO
OUTPUT "Your temperature must be between -20.0 and +50.0 inclusive. Please try
again"
INPUT InTemp
ENDWHILE
Readings[WeekLoop, DayLoop]  InTemp
// totalling of temperatures during the day
TotalDayTemp  TotalDayTemp + ROUND(InTemp, 1)
NEXT DayLoop

// average temperature for the day

AverageTemp[WeekLoop]  ROUND(TotalDayTemp / 24,1)
NEXT WeekLoop
// calculate the average temperature for the week
TotalWeekTemp  0
FOR WeekLoop  1 TO 7
TotalWeekTemp  TotalWeekTemp + AverageTemp[WeekLoop]
NEXT WeekLoop

AverageWeekTemp  ROUND(TotalWeekTemp / 7,1)

// outputs in Celsius and Fahrenheit
FOR WeekLoop  1 TO 7
OUTPUT "The average temperature on ", Days[WeekLoop], " was ", AverageTemp[WeekLoop], "
Celsius and ",
ROUND(AverageWeekTemp * 9 / 5 + 32), 1, " Fahrenheit"
NEXT WeekLoop

OUTPUT "The average temperature for the week was ",

AverageWeekTemp," Celsius and ", ROUND(AverageWeekTemp * 9 / 5 + 32, 1),"
Fahrenheit"

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Marking Instructions in italics

AO2: Apply knowledge and understanding of the principles and concepts of computer science to a given context, including the
analysis and design of computational or programming problems

0 1–3 4–6 7–9

At least one programming technique has Some programming techniques used are The range of programming techniques
been used. appropriate to the problem. used is appropriate to the problem.

Any use of selection, iteration, counting, More than one technique seen applied All criteria stated for the scenario have
totalling, input and output. to the scenario, check the list of been covered by the use of appropriate
techniques needed. programming techniques, check the list
No creditable of techniques needed.
response.
Some data has been stored but not Some of the data structures chosen are The data structures chosen are
appropriately. appropriate and store some of the data appropriate and store all the data
required. required.
Any use of variables or arrays or other
language dependent data structures e.g. More than one data structure used to The data structures used store all the
Python lists. store data required by the scenario. data required by the scenario.

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Marking Instructions in italics

AO3: Provide solutions to problems by:

 evaluating computer systems
 making reasoned judgements
 presenting conclusions

0 1–2 3–4 5–6

Program seen without relevant Program seen with some relevant The program has been fully commented.
comments. comment(s).

Some identifier names used are The majority of identifiers used are Suitable identifiers with names
appropriate. appropriately named. meaningful to their purpose have been
used throughout.
Some of the data structures used have Most of the data structures used have
meaningful names. meaningful names. All of the data structures used have
meaningful names.

The solution is illogical. The solution contains parts that may be The program is in a logical order.
illogical.
No creditable The solution is inaccurate in many The solution contains parts that are The solution is accurate.
response. places. inaccurate.
Solution logically performs all the tasks
Solution contains few lines of code with Solution contains lines of code with given in the scenario. Ignore minor
errors that attempt to perform a task some errors that logically perform tasks syntax errors.
given in the scenario. given in the scenario. Ignore minor
syntax errors.

The solution attempts at least one of the The solution meets most of the The solution meets all the requirements
requirements. requirements. given in the question.

Solution contains lines of code that Solution contains lines of code that Solution performs all the tasks given in
attempt at least one task given in the perform most tasks given in the the scenario.
scenario. scenario.

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 Theory October/November 2022
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2022 series for most
Cambridge IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level
components.

This document consists of 15 printed pages.

© UCLES 2022 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme October/November 2022
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

Please note the following further points:

The words in bold in the mark scheme are important text that needs to be present, or some notion of it needs to be present. It does not have to
be the exact word, but something close to the meaning.

If a word is underlined, this exact word must be present.

A single forward slash means this is an alternative word. A double forward slash means that this is an alternative mark point.

Ellipsis (…) on the end of one-mark point and the start of the next means that the candidate cannot get the second mark point without being
awarded the first one. If a mark point has an ellipsis at the beginning, but there is no ellipsis on the mark point before it, then this is just a follow-on
sentence and can be awarded without the previous mark point.

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Question Answer Marks

1(a) One mark for a correct device and one mark for a corresponding example 2

• Keyboard
• … e.g. to type In a shop name

• Mouse
• … e.g. to click on a shop

• Microphone
• … e.g. to speak the shop name as a voice command

• Touchscreen
• … e.g. to select a shop

• Barcode scanner
• … e.g. to scan a barcode for a voucher

• Sensor
• … e.g. to detect when a person walks past

• Digital camera // webcam

• … e.g. to video call for assistance

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Question Answer Marks

1(b) One mark for a correct device and one mark for a corresponding example 2

• Display screen / monitor / touchscreen

• … e.g. to see a shops location

• Speaker // headphones
• …. e.g. to hear where a shop is located

• Printer
• …. e.g. to get a hard copy of shop information

• LED/Light
• … e.g. to indicate where a shop is on the map

1(c) One mark for a correct storage and one mark for a corresponding example 2

• Random access memory // RAM

• … to store data the is currently being processed
• … to store the OS/programs/applications whilst in use

• Read only memory // ROM

• … to store the start-up instructions
• … to store the BIOS

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Question Answer Marks

2(a) One mark for each correct bus (max 2) and one mark for corresponding description of transmission 4

• Data bus
• …. responsible for transmitting data/instructions

• Control bus
• … responsible for transmitting control signals

2(b) Any one from: 1

• Fetch
• Decode

2(c) Any two from: 3

• To temporarily store data

• It stores the result of interim calculations

One from:

• Arithmetic logic unit / ALU

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Question Answer Marks

3(a) One mark for two correct characters, two marks for three, in the correct place 2

• 0100 0000 0100

3(b) One mark for two correct characters, two marks for three 2

• 0001 0010 1011

3(c) One mark for each correct denary conversion 2

• 34
• 172

3(d) One mark for two correct characters, two marks for three, in the correct place 2

• 9E0

3(e) Any two from: 2

• It is easier for user to read/recognise/understand

• It takes up less space on a display

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Question Answer Marks

4(a) One mark for identification of the method (max 2), two marks for describing how the method could be used 6

• Phishing
• A legitimate looking email is sent to her, asking her to click a link
• … this takes her to a fake website where she enters her bank details

• Pharming
• She accidentally downloads malicious software onto her computer
• … this redirects her legitimate website requests to a fake website where she enters her bank details

• Hacking
• A person gains unauthorised access to her computer
• .. they steal/view a data file that contains her bank details

• Spyware
• Records the key presses on her computer
• … this data is analysed for patterns and her bank details are identified

4(b)(i) • The data will be meaningless if it is stolen 1

4(b)(ii) One from: 4

• Data is encrypted and decrypted using the same key/algorithm

Any three from:

• Data before encryption is known as plain text

• Data after encryption is known as cypher text
• Key is sent to receiver (to allow data to be decrypted) // Values are sent to receiver that are used to generate key

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Question Answer Marks

4(b)(iii) Any three from: 3

• Firewall // proxy server

• Password
• Biometric device
• Virtual measure e.g. onscreen keyboard
• Two-step verification // two factor authentication
• Physical methods
• Antimalware // Antispyware // Antivirus

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Question Answer Marks

5(a) One mark for each correct logic gate with correct input(s) 6

5(b) Any one from: 1

• NOR
• XOR // EOR

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Question Answer Marks

5(c) Four marks for 8 correct outputs 4

Three marks for 6/7 correct outputs
Two marks for 4/5 correct outputs
One mark for 2/3 correct outputs

A B C Working space X

0 0 0 1

0 0 1 1

0 1 0 1

0 1 1 1

1 0 0 1

1 0 1 1

1 1 0 0

1 1 1 1

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Question Answer Marks

6 One from: 3

• Interrupt

Any two from e.g.:

• Paper jam
• Paper tray empty
• Any change of task example
• Any error occurrence example

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Question Answer Marks

7(a) • Low-level language 1

7(b) • Assembler 1

7(c) Any two from: 2

• He can directly access the hardware

• He can use special machine-dependent instructions
• There is no need for the program to be portable
• Smaller file size // takes up less storage space
• More efficient use of memory
• Programs will be more time efficient when running

7(d) Any two from: 2

• Programs are not portable

• It is complex to learn
• Difficult to debug

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Question Answer Marks

8(a)(i) Any two from e.g.: 2

• Background colour
• Font colour
• Font size
• Font style

8(a)(ii) Any two from e.g.: 2

• Placement of text
• Placement of image

8(b) Any five from: 5

• Web browser sends request to web server

• … to view the digital certificate
• Web server sends the digital certificate to the web browser
• Web browser checks the certificate for authenticity
• If certificate is authentic a secure connection is created
• Any data sent is encrypted
• If certificate is not authentic the connection is rejected
• Uses a protocol such as SSL/TLS

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PUBLISHED
Question Answer Marks

8(c) Any two from: 4

• A (small) text files

• … that is stored by the browser
• … sent between web server and browser when user visits the website

Any two from e.g.:

• To track users browsing habits

• To store personal details
• To tailor web page to user's presentation requirements
• To store items in a virtual shopping cart
• To tailor adverts to a user

8(d) One from: 4

• Proxy server

Any three from:

• It examines the incoming traffic to server

• It limits the number of requests to the website
• … preventing too many requests that could overwhelm the server
• Block multiple requests from the same IP within a timeframe

© UCLES 2022 Page 15 of 15

Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 Problem-solving and Programming October/November 2022
MARK SCHEME
Maximum Mark: 50

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2022 series for most
Cambridge IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level
components.

This document consists of 9 printed pages.

© UCLES 2022 [Turn over

0478/21 Cambridge IGCSE – Mark Scheme October/November 2022
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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PUBLISHED
GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

Please note the following further points:

The words in bold in the mark scheme are important text that needs to be present, or some notion of it needs to be present. It does not have to
be the exact word, but something close to the meaning.

If a word is underlined, this exact word must be present.

A single forward slash means this is an alternative word. A double forward slash means that this is an alternative mark point.

Ellipsis (…) on the end of one-mark point and the start of the next means that the candidate cannot get the second mark point without being
awarded the first one. If a mark point has an ellipsis at the beginning, but there is no ellipsis on the mark point before it, then this is just a follow-on
sentence and can be awarded without the previous mark point.

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0478/21 Cambridge IGCSE – Mark Scheme October/November 2022
PUBLISHED
Question Answer Marks

Section A

1(a)(i) Many correct answers, the names used must be meaningful. The names given are examples only. 5

One mark per mark point, max five

MP1 name one e.g. Name, Age, Gender, Type, TeamMember, AnnualFee, Paid
MP2 one appropriate data type must match name e.g. string, integer, char, string, Boolean, real, Boolean
MP3 sample data for one appropriate array
MP4 all arrays mentioned have appropriate names
MP5 all arrays mentioned have appropriate data types
MP6 sample data for all arrays e.g. Sue, 9, F, Junior, True, 9.00, False

1(a)(ii) One mark per mark point, max two 2

MP1 use a loop e.g. FOR…NEXT / REPEAT…UNTIL / WHILE…DO

MP2 to input the values for each element in every array
MP3 append each value input to the end of the array

1(b) One mark per mark point, max two 2

MP1 use a loop/ FOR/REPEAT/WHILE to check all members

MP2 use a conditional statement / IF to see if the paid field is marked as False
MP3 only transfer the data of those members whose paid field is marked as True to a set of new arrays
// delete the details of the members who have not paid

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Question Answer Marks

1(c) One mark per mark point, max six 6

MP1 loop through all the members

MP2 any suitable correct comparison of age
MP3 if 18 Change membership type to adult
MP4 if 50 Change membership type to senior
MP5 if 80 Change membership type to golden
MP6 check if team member
MP7 no store appropriate full fee
MP8 yes store 90% of appropriate full fee

Example
FOR Member  1 TO Total
CASE Age[Member] OF
18 : Type[Member]  "Adult"
50 : Type[Member]  "Senior"
80 : Type[Member]  "Golden"
ENDCASE

IF Team[Member]
THEN
CASE Type[Member] OF
"Junior" : Fee[Member]  JuniorFee * 0.9
"Adult" : Fee[Member]  AdultFee * 0.9
"Senior" : Fee[Member]  SeniorFee * 0.9
ENDCASE
ELSE
CASE Type[Member] OF
"Junior" : Fee[Member]  JuniorFee
"Adult" : Fee[Member]  AdultFee
"Senior" : Fee[Member]  SeniorFee
"Golden" : Fee[Member]  GoldenFee
ENDCASE
ENDIF
NEXT Member
© UCLES 2022 Page 5 of 9
0478/21 Cambridge IGCSE – Mark Scheme October/November 2022
PUBLISHED
Question Answer Marks

1(d) Explanation 5

One mark per mark point, max five

MP1 how the program checked all the members // use of loop
MP2 how the program identified a member who has not paid their (annual) fee // use of condition
MP3 how the program kept a running total of members who have not paid their (annual) fees
MP4 for each of the three types of membership that require a fee // excluding golden members
MP5 how the program calculated a percentage for members who had not paid…
MP6 for each of the three types of membership that require a fee
MP7 how the program displayed a percentage for members who had not paid
MP8 all three percentages displayed with suitable messages

Programming statements when used must be explained.

Question Answer Marks

Section B

2(a) One mark per mark point, max six 6

• Line 1 100
• Line 7 Value > 100 // Value >= 101
• Line 11 Reading[Value] + 1
• Line 14 INPUT Value
• Line 18 Reading[Count]
• Line 19 Count – 1

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Question Answer Marks

2(b) One mark per mark point, max three 3

• use an IF/conditional statement

• to check if Reading[Count] not equal to zero
• before outputting the value // between statements 17 and 18 // code sample showing position

IF Reading[Count] <> 0
THEN
OUTPUT
ENDIF

Question Answer Marks

3(a) Two marks per check, description must match name of check if given, max six 6

• Check 1 use a type check

o to ensure that the value is a number / integer
• Check 2 use a length check
o to ensure that there are only 4 characters / digits
• Check 3 use a range check
o to ensure that the value is >= 1000 and <=9999

3(b) One mark per mark point, max three 3

MP1 input the new PIN

MP2 input the new PIN again // ask the user to check the number on screen
MP3 check that both PINs are the same // confirm that it is the PIN to use
MP4 check that the new PIN is not the same as the old PIN

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Question Answer Marks

4(a) One mark for each correct column, max four 4

Sold Stock Total OUTPUT

50 0

24 26 24

12 14 Add new stock

64 36

6 58 42

30 28 72

12 16 Add new stock

66 84

18 48 102

-1 102

4(b) One mark for identification of error, max one 3

• the stock level will fall below zero / become negative

One mark per mark point, max two

• before subtracting the amount Sold from Stock

• test that the stock level / Stock is greater than the rolls to be sold / Sold
• provide a suitable error message / ask to re-input

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Question Answer Marks

5(a) One mark per mark point, max two 2

• ItemCode
• uniquely identifies each item

5(b) One mark per mark point, max three 3

• correct rows Field, Table and Sort

• correct row Show
• correct Criteria row <10 or <=9

Field: ItemCode Manufacturer Level

Table: WAREHOUSE WAREHOUSE WAREHOUSE

Sort:

Show:    

Criteria: <10

or:

© UCLES 2022 Page 9 of 9

Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 Theory May/June 2022
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the May/June 2022 series for most
Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some
Cambridge O Level components.

This document consists of 13 printed pages.

© UCLES 2022 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme May/June 2022
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

 the specific content of the mark scheme or the generic level descriptors for the question
 the specific skills defined in the mark scheme or in the generic level descriptors for the question
 the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

 marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
 marks are awarded when candidates clearly demonstrate what they know and can do
 marks are not deducted for errors
 marks are not deducted for omissions
 answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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0478/11 Cambridge IGCSE – Mark Scheme May/June 2022
PUBLISHED
GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

Please note the following further points:

The words in bold in the mark scheme are important text that needs to be present, or some notion of it needs to be present. It does not have to
be the exact word, but something close to the meaning.

If a word is underlined, this exact word must be present.

A single forward slash means this is an alternative word. A double forward slash means that this is an alternative mark point.

Ellipsis (…) on the end of one-mark point and the start of the next means that the candidate cannot get the second mark point without being
awarded the first one. If a mark point has an ellipsis at the beginning, but there is no ellipsis on the mark point before it, then this is just a follow-on
sentence and can be awarded without the previous mark point.

© UCLES 2022 Page 3 of 13

0478/11 Cambridge IGCSE – Mark Scheme May/June 2022
PUBLISHED
Question Answer Marks

1(a)(i)  Sound 1

1(a)(ii)  Lossy compressed file 1

Question Answer Marks

2(a)(i)  Random access memory // RAM 1

2(a)(ii) One mark for each correct stage 2

Second stage
 Decode

Third stage
 Execute

2(a)(iii) Any two from: 2

 Memory address register // MAR
 Memory data register //MDR
 Program counter // PC
 Control unit // CU
 Address bus
 Data bus
 Control bus

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0478/11 Cambridge IGCSE – Mark Scheme May/June 2022
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Question Answer Marks

3(a) Any one from e.g.: 1

 SD card
 USB flash memory drive
 Random access memory // RAM

3(b) Any three from: 3

 Laser is shone at the disk

 An (arm/head) moves the laser across the surface of the disk
 The laser burns pits onto the surface of the disk
 The laser is used to read the pits and lands on the surface of the disk
 The reflected light from the laser shining on the disk is captured (by a sensor)

3(c)(i) Any three from: 3

 It is small in size // compact // lightweight // portable

 It has low power consumption
 It runs quietly
 It runs at a cool temperature
 It is robust when dropped // durable
 Fast access/read/write speed
 High capacity
 Not affected by magnets

3(c)(ii)  Operating system 2

 Application software // by example
 Utility software // by example

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Question Answer Marks

4(a)  Computer consist of transistors / logic circuits/gates … 2

 … that can only store/process data in two states / high-low / on-off / 1 and 0

4(b)  01000000 3
 01100101
 11110010

4(c)  0100 (1 mark) 0010 (1 mark) 4

 1100 (1 mark) 1110 (1 mark)

Question Answer Marks

5 Two marks for two correct stages of working, one mark for correct final answer 3

 100  150
 15 000  16 // 15 000  2
 240 000 / 8

 30 000 bytes

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Question Answer Marks

6(a)(i)  They both report/check for errors 1

6(a)(ii) Four from (MAX 2 per translator): 4

 An interpreter translates the code line by line (and executes each line immediately)
 … whereas a compiler translates the whole code at the same time (before executing it)

 A compiler produces an executable file

 … but an interpreter does not

 An interpreter is required to run the code each time if used

 … whereas a compiler is not

 An interpreter stops and reports an error as it is encountered

 … whereas a compiler creates a report of all errors at the end of translation

 An interpreter will run code up to the point it finds an error

 … whereas a compiler will not run the code at all if an error is found

Question Answer Marks

7(a) Any one from: 1

 Uses biological data
 It uses characteristics/features that belong to a human

7(b) Any two from: 2

 A biometric password cannot be guessed
 It is very difficult to fake a biometric password
 A biometric password cannot be recorded by a keylogger/spyware
 A perpetrator cannot shoulder surf to see a biometric password

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Question Answer Marks

7(c) Any three from: 3

 The traffic/data is compared to set criteria/rules/whitelist/blacklist

 If the traffic/data does/does not meet the criteria/rules/whitelist/blacklist it will be rejected/blocked …
 … and an alert can be sent to warn Adele
 … this can help prevent hackers/malicious software (gaining access to the data)

7(d)  It makes the data meaningless 1

Question Answer Marks

8(a) One mark for each correct logic gate with correct input(s) 6

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Question Answer Marks

8(b) Four marks for 8 correct outputs 4

Three marks for 6/7 correct outputs
Two marks for 4/5 correct outputs
One mark for 2/3 correct outputs

A B C Working space X

0 0 0 0

0 0 1 1

0 1 0 0

0 1 1 1

1 0 0 0

1 0 1 1

1 1 0 0

1 1 1 1

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Question Answer Marks

9(a) One mark for each correct row: 5

Statement Browser IP address URL

() () ()

it contains the domain name 

it is a type of software 

it converts Hypertext Markup 

Language (HTML) to display web pages

it is a type of address  

it stores cookies 

Question Answer Marks

10 Any three from: 3

 It is a unique address
 It is assigned by the manufacturer
 It can be used to identify a device
 It contains the manufacturer ID/code/number
 It contains the serial code/number
 It is written in hexadecimal
 It has 6 bytes/48 bits/6 pairs of digits
 Does not (usually) change // static

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Question Answer Marks

11(a) One mark for each of the correct terms, in the correct place 5
 buffer
 nozzles
 liquid
 thermal bubble
 interrupt

11(b) Any three from e.g.: 3

 Monitor // screen
 Speaker
 Headphones
 Light // LED
 (2D/3D) cutter
 DLP // LCD projector
 Actuator

11(c) Any two from e.g.: 3

 Keyboard
 Mouse // trackerball
 Microphone
 (2D/3D) scanner
 Barcode reader
 QR code reader
 Digital camera // webcam
 Interactive whiteboard
 Touchscreen
 Sensor

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Question Answer Marks

12 One mark for identification of an issue and one mark for a description e.g.: 6

 Plagiarism
– The copying of other people’s work without their permission
– Claiming someone else’s work as your own

 Hacking
– Unauthorised access to a computer/data

 Malware
– Malicious software designed to damage a computer system or stored data

 Spyware
– Keylogger used to record keypresses and sends them to third party

 Ransomware
– Holding hostage a user’s data, often for a release fee

 Intellectual property theft

– Stealing other people work

 Breaching copyright
– Breaking the law by copying someone’s work

 Piracy
– Using piracy websites to gain content for free that should have been paid for

 Privacy
– A person’s data could be leaked

 Phishing
– Sending an email to lure users to a fake site to obtain their personal details

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Question Answer Marks

12  Pharming
– Downloading of malicious code to redirect user to fake website to obtain their personal details

 Data protection
– A person’s data is not used according to the law

 Cyber bullying
– Using the internet to bully people

 Inappropriate materials
– Materials that could cause harm/offense to people e.g. minors

 Fake news
– News stories that could be very misleading or harmful

 Software cracking
– Changing code to e.g. bypass a licence for software

 Addiction
– Aspects of the internet e.g. social media can cause this

 Environmental effects
– Increased use of the internet increases the use of electrical power

© UCLES 2022 Page 13 of 13

Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 Problem Solving and Programming May/June 2022
MARK SCHEME
Maximum Mark: 50

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the May/June 2022 series for most
Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some
Cambridge O Level components.

This document consists of 13 printed pages.

© UCLES 2022 [Turn over

0478/21 Cambridge IGCSE – Mark Scheme May/June 2022
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

 the specific content of the mark scheme or the generic level descriptors for the question
 the specific skills defined in the mark scheme or in the generic level descriptors for the question
 the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

 marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
 marks are awarded when candidates clearly demonstrate what they know and can do
 marks are not deducted for errors
 marks are not deducted for omissions
 answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

© UCLES 2022 Page 2 of 13

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PUBLISHED
GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

© UCLES 2022 Page 3 of 13

0478/21 Cambridge IGCSE – Mark Scheme May/June 2022
PUBLISHED
Please note the following further points:

The words in bold in the mark scheme are important text that needs to be present, or some notion of it needs to be present. It does not have to
be the exact word, but something close to the meaning.

If a word is underlined, this exact word must be present.

A single forward slash means this is an alternative word. A double forward slash means that this is an alternative mark point.

Ellipsis (…) on the end of one-mark point and the start of the next means that the candidate cannot get the second mark point without being
awarded the first one. If a mark point has an ellipsis at the beginning, but there is no ellipsis on the mark point before it, then this is just a follow-on
sentence and can be awarded without the previous mark point.

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Question Answer Marks

Section A

1(a) One mark per mark point, max five 5

Data Structure(s), max two

MP1 arrays
MP2 variable(s) / constant(s)
Further description, max three
MP3 name(s) one or more
MP4 sample data for appropriate arrays or variables
MP5 use(s) one or more
Additional data structure description using the same data structure type, max one
MP6 two or more full descriptions of the data structure including name, sample data and use

For example:
An array (1) named FirstName (1) to store the first names of the members (1) such as James (1). A variable (1) could also
be used to enter whether or not they wish to volunteer. (5 marks)

A variable (1) named FirstName (1) to input the first names of the members (1) such as James (1). A variable could also be
used to enter whether or not they wish to volunteer, with sample data of ‘yes’ (1). (5 marks)

Task 1 – becoming a member of Friends of Seaview Pier

Set up a system to enable people to become members of Friends of Seaview Pier and for each new member enter:
 their first name and last name
 whether or not they wish to work as a volunteer
– if they choose to volunteer, identify the area from:
o the pier entrance gate
o the gift shop
o painting and decorating
 the date of joining
 whether or not they have paid the $75 fee.
All of this information needs to be stored using suitable data structures.

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Question Answer Marks

1(b) Explanation of how each was done. Code is allowed, but must be fully explained. 3

One mark per mark point, max three

MP1 add/use a (new) variable/array to total the membership fee money // total number of members who have paid
MP2 initialise the totalling variable to 0 at the start of the program
MP3 check whether the new member has paid the $75 fee using a conditional statement
MP4 …if they have paid, and the amount paid is being totalled, add 75 to the current running total of the membership
fee total
MP5 …if they have paid, and the number of paid members is being totalled, add 1 to the total number of members who
have paid
MP6 …if they have paid, and the number of paid members is being totalled, multiply total by 75, to give total paid.

1(c) Any code must include a description of what it is for. 3

One mark per mark point, max three

Max two for just naming different appropriate validation checks

MP1 apply a presence check // to ensure that data has been entered (to the question do you want to work as a
volunteer?)
MP2 apply a type check // to ensure that data has been entered of the correct data type e.g. integer if the response
required is 1 or 0
MP3 checking the valid inputs would be either yes or no // apply a check to ensure that the data matches the expected
input
MP4 the valid inputs would be to choose in which area the new member wishes to volunteer e.g. a list of areas
MP5 if input is not valid, an error message is output (and a new input is requested)
MP6 if input is valid, the program continues

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PUBLISHED
Question Answer Marks

1(d) One mark per mark point, max five 5

MP1 input for sponsor’s name / name taken from previous data // input for message on plaque
MP2 both inputs correct with appropriate prompts // input for message on plaque correct with appropriate prompt and
name taken from previous data
MP3 output of input(s) for confirmation …
MP4 … method for sponsor to confirm that the input(s) are correct
MP5 method to enable re-entry of message on plaque if errors made
MP6 charge of $200 acknowledged / charged / confirmed / displayed
MP7 (name and) message stored in arrays
MP8 array index incremented for next sponsor

Task 3 – sponsoring a wooden plank

Add an additional option to the program in Task 1 to enable the pier’s wooden planks to be sponsored. Separate data
structures should be used to store the names of the individuals and the short messages they would like to have written on
their brass plaque. An output would display everything that was input for the sponsor to confirm. If errors are found, the
program should allow data to be re-entered. Once complete, the data is stored and the sponsor is charged $200.

Example answer
ArrayIndex  0 //initial array's index
Check  "N"
WHILE Check <> "Y"
OUTPUT "Enter your name"
INPUT Name
OUTPUT "Enter the message you would like on your brass plaque"
INPUT Message
OUTPUT "The data you have entered is, name: ", Name, " and your
message for the plaque is: ", Message
OUTPUT "Is this correct (Y or N)"
INPUT Check
IF Check <> "Y"
THEN
OUTPUT "The data entered is incorrect, please re-enter"
ENDIF
ENDWHILE

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Question Answer Marks

1(d) PlankName[ArrayIndex]  Name

Message[ArrayIndex]  Message
ArrayIndex  ArrayIndex + 1
OUTPUT "The fee for this service is $200"
//some method of paying the fee or acknowledgement of the fee

1(e) Explanation of how each was done. Code is allowed, but must be fully explained. 4

One mark per mark point, max four

MP1 a menu is provided/options are displayed so that the user can choose which of the lists they wish to see
MP2 the user inputs a number/code as shown on the menu corresponding to their menu choice
MP3 attempt to validate input
MP4 … if it does not match an option, give an error message and ask for re-input
MP5 … if it matches an option, a range of IF statements/conditional statements/CASE statement are/is used to
compare the input with the available options
MP6 … output the chosen list e.g. using a loop to output the contents of the appropriate first and second name arrays
corresponding to the user input
MP7 identification of empty list and appropriate action

Task 2 – using the membership data

Extend the program in Task 1 so that a list of the first and last names of members can be output in any of the following
categories:
 Members who have chosen to work as volunteers.
 Volunteers who would like to work at the pier entrance gate.
 Volunteers who would like to work in the gift shop.
 Volunteers who would like to help with painting and decorating tasks.
 Members whose membership has expired (they have not re-joined this year).
 Members who have not yet paid their $75 fee.

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Question Answer Marks

Section B

2 Four marks for five correct rows 4

Three marks for four correct rows
Two marks for three correct rows
One marks for two correct rows

Data type
Description
Boolean Char Integer Real String

a single character from the keyboard 

multiple characters from the keyboard 

only one of two possible values 

only whole numbers 

any number 

Question Answer Marks

3 One mark per mark point, max four 4

 Normal test data computerscience@cambridge.org.uk

 Reason this is a valid email address (containing the @ symbol) and should be accepted

 Erroneous test data computerscienceisgreat

 Reason this is just a string, and should be rejected (as an email address needs a single ’@’)

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Question Answer Marks

4(a) One mark per mark point, max six 6

MP1 input box

MP2 correct check of Score
MP3 assign Score to Pass correctly
MP4 assign Score to Fail correctly
MP5 increment both array counters
MP6 correct check of number of scores

START

PassCount  0

FailCount  0

Count  0

INPUT
Score

Yes IS Score >= No

50?

Pass[PassCount]  Score Fail[FailCount]  Score

PassCount  PassCount + 1 FailCount  FailCount + 1

Count  Count + 1

No IS Count =
60?

Yes
END

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Question Answer Marks

4(b) One mark per mark point, max four 4

MP1 appropriate conditional loop structure

MP2 correct identification of invalid input
MP3 appropriate error message
MP4 repeated input of score until correct

WHILE Score < 0 OR Score > 100 (DO)

OUTPUT "Your entry must be between 0 and 100, inclusive, please try again "
INPUT Score
ENDWHILE

Or:

REPEAT
IF Score < 0 OR Score > 100
THEN
OUTPUT "Your entry must be between 0 and 100, inclusive, please try again "
INPUT Score
ENDIF
UNTIL Score >= 0 AND Score <= 100

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Question Answer Marks

5(a) One mark per mark point, max five 5

MP1 correct Counter and Limit columns

MP2 correct Value column
MP3 correct First column
MP4 correct Last column
MP5 correct OUTPUT

Counter Value First Last Limit OUTPUT

0 0 8

1 66

2 606 6 6 606

3 6226

4 8448

5 642 6 2

6 747 7 7 747

7 77

8 121 1 1 121

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Question Answer Marks

5(b) One mark per mark point, max two 2

 checks for / outputs 3-digit numbers
 … where the first and last digit are the same

Question Answer Marks

6(a) 8 1

6(b) The primary key field must be unique/different for each record in the table 1

6(c) One mark per mark point, max three 3

 correct fields and table named correctly

 correct sort and show box rows
 correct search criteria

Field: GameID GameName GamePrice NumberStock OnOrder

Table: GAMES GAMES GAMES GAMES GAMES

Sort: Ascending

Show:     

Criteria: =0 ="Y"

or:

© UCLES 2022 Page 13 of 13

Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 October/November 2021
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2021 series for most
Cambridge IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level
components.

This document consists of 8 printed pages.

© UCLES 2021 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme October/November
PUBLISHED 2021

Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers.
They should be applied alongside the specific content of the mark scheme or generic level descriptors
for a question. Each question paper and mark scheme will also comply with these marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit
is given for valid answers which go beyond the scope of the syllabus and mark scheme,
referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these
features are specifically assessed by the question as indicated by the mark scheme. The
meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed
instructions or in the application of generic level descriptors.

GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question
(however; the use of the full mark range may be limited according to the quality of the candidate
responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should
not be awarded with grade thresholds or grade descriptors in mind.

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Question Answer Marks

1(a) − Base-2 1

1(b) − 9 4
− 16
− 40
− 161

Question Answer Marks

2(a) − Microphone 1

2(b) − capacitive 1

2(c) − interrupt 1

Question Answer Marks

3(a) One mark per each correct row. 5

Statement Checksum Check Parity

() digit check
() ()

uses an additional bit to create an 

odd or even number of 1s

checks for errors on data entry 

compares two calculated values to  

see if an error has occurred

will not detect transposition errors 

sends additional values when data is  ()

transmitted from one computer to
another

3(b) − ARQ 1

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Question Answer Marks

4(a) Two marks for any two correct workings and one mark for the correct 3
answer.

Working:
− 100 × 50 = 5000 bits
− 5000 × 8 = 40,000 bits
− 40,000 / 8 = 5,000 bytes
− 5,000 × 10 = 50,000 bytes
− 50,000 / 1024

Answer:
48.83 kB // 49 kB

NOTE: Alternative correct methods of working can be credited. Answer can

be given to any number of dp.

4(b) One mark per correct method, two marks per justification. 3

− Lossless

− Lossy would remove data permanently // lossless would not remove any
data permanently // File could be restored to original …
− … that could affect the quality (lossy) // … to maintain the quality
(lossless)

4(c) − Light 5
− Lens
− Charge-coupled
− Analogue-to-digital
− Pixel

Question Answer Marks

5(a) Any two from: 2

− Encryption
− Biometric device
− Firewall
− Anti-spyware
− Two-factor authentication // two-step verification

5(b) Any two from: 2

− Interrupt / error-handling
− Peripheral management
− Providing user interface
− Platform for running applications // installing / removing software
− Manages security // access rights/levels // user account management
− Managing time slicing // multitasking

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Question Answer Marks

6(a) One mark per each correct row. 6

Statement MAR MDR PC

() () ()

it is a register in the CPU   

it holds the address of the next instruction to () 

be processed

it holds the address of the data that is about  ()

to be fetched from memory

it holds the data that has been fetched from 

memory

it receives signals from the control unit   

it uses the address bus to send an address  

to another component

6(b) − Arithmetic Logic Unit // ALU 1

Question Answer Marks

7(a) One mark per correct storage, two marks for justification. 3

− Secondary

− It is non-volatile storage
− It is not directly accessed by the CPU

7(b) Any four from: 4

− Uses flash memory
− Data is flashed onto (silicon) chips
− Uses NAND/NOR technology // Can use flip-flops
− Uses transistors/control gates/floating gates …
− … to control the flow of electrons
− It is a type of EEPROM technology
− When data is stored the transistor is converted from 1 to 0 / 0 to 1
− Writes (and reads) sequentially

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Question Answer Marks

8(a) − High-level 1

8(b)(i) One mark for the correct translator, two marks for the benefit(s). 3

− Interpreter
− Easier to debug
− … as errors are immediately reported when detected

− Compiler
− All errors are reported in a single report
− … meaning they can all be fixed at the same time
− No need to recompile code every time a test is run

8(b)(ii) One mark for the correct translator, two marks for the benefits. 3

− Compiler
− Creates an executable file
− … so, translator is no longer needed to run it
− Source code cannot be stolen // can be provided without the source code

Question Answer Marks

9(a) One mark per each correct sensor. 3

Task Sensor

checking the water is 30 °C Temperature

checking the water acidity level after detergent is pH

added

checking the weight of the clothes to make sure that Pressure

the machine is not overloaded

9(b) Six from: 6

− Sensor sends data to microprocessor

− Data is converted from analogue to digital (using ADC)
− Data is compared to stored value (of 30)

If data is below 30 then a microprocessor sends signal is sent to a heater

to heat the water up/add hot water
− if data is above 30 then a microprocessor sends signal is sent to turn
the heater off to allow the water to cool down/add cold water
− Actuator used to turn headset on/off // Actuator used to add water
− If data is 30 then no action is taken
− It is a continuous process

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Question Answer Marks

10(a) One mark per each correct logic gate with the correct input(s). 5

10(b) One mark per logic gate name and one mark per correct drawing. 2

− NAND

− NOR

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Question Answer Marks

10(c) 4
A B C Working space X

0 0 0 0

0 0 1 0

0 1 0 0

0 1 1 1

1 0 0 0

1 0 1 1

1 1 0 0

1 1 1 1

4 marks per 8 correct outputs

3 marks per 6/7 correct outputs
2 marks per 4/5 correct outputs
1 mark per 2/3 correct outputs

Question Answer Marks

11 One mark per each correct term. 5

Terms Description

HTML the language used to create a web page

Browser the type of software application used to display a

web page

IP address an address given to a computer, by a network, to

allow the computer to be uniquely identified

Cookie a text file sent by a web server to collect data about

a user’s browsing habits

Internet Service the company that provides a connection to the

Provider // ISP Internet

© UCLES 2021 Page 8 of 8

Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 October/November 2021
MARK SCHEME
Maximum Mark: 50

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2021 series for most
Cambridge IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level
components.

This document consists of 11 printed pages.

© UCLES 2021 [Turn over

0478/21 Cambridge IGCSE – Mark Scheme October/November 2021
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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0478/21 Cambridge IGCSE – Mark Scheme October/November 2021
PUBLISHED
GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

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Question Answer Marks

Section A

1(a) Constant NoCourts // NoSessions // NoBookingSlots 3

Value 8 // 10 // 80
Use Storing the number of courts / sessions available / times and courts available for booking

1(b) Any four from: 4

Any three from

MP1 Identifier / name of array used
MP2 Description of purpose of an identified array
MP3 Length of an identified array used
MP4 Type of data in an identified array
MP5 Explanation of number of arrays used, must be capable of storing all data required
MP6 Sample data for an identified array

One mark
MP7 Identifying more than one array

E.g.4 arrays of ten elements for each squash court, for example for squash court 1 Availability1 of type Boolean,
Guest1, Mobile1 and Code1 all type string

1(c) Any three from: 3

MP1 Setting the first code number

MP2 How to find subsequent code numbers
MP3 How to ensure they were unique
MP4 How to ensure they were exactly 4 digits

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Question Answer Marks

1(d) Any six from: 6

MP1 Input time
MP2 … with prompt
MP3 Check each court
MP4 If court not booked …
MP5 … set as booked
MP6 Input name, mobile number
MP7 Calculate unique 4-digit code
MP8 Store name, mobile number and 4-digit code in an array
MP9 Display mobile number and 4-digit code with suitable message
MP10 Change mobile number if necessary

Sample
OUTPUT ("Which time do you want to book a squash court")
INPUT BookTime
Booked ← FALSE
CourtNumber ← 0
IF BookTime >= 8 AND BookTime <= 17
THEN
BookTime ← BookTime - 7
IF Available1[BookTime] THEN Available1[BookTime] ← FALSE; CourtNumber ← 1; Booked ←
TRUE ENDIF
IF NOT Booked AND Available2[BookTime] THEN Available2[BookTime] ← FALSE; CourtNumber
← 2; Booked ← TRUE ENDIF
IF NOT Booked AND Available3[BookTime] THEN Available3[BookTime] ← FALSE; CourtNumber
← 3; Booked ← TRUE ENDIF
IF NOT Booked AND Available4[BookTime] THEN Available4[BookTime] ← FALSE; CourtNumber
← 4; Booked ← TRUE ENDIF
IF NOT Booked AND Available5[BookTime] THEN Available5[BookTime] ← FALSE; CourtNumber
← 5; Booked ← TRUE ENDIF
IF NOT Booked AND Available6[BookTime] THEN Available6[BookTime] ← FALSE; CourtNumber
← 6; Booked ← TRUE ENDIF
IF NOT Booked AND Available7[BookTime] THEN Available7[BookTime] ← FALSE; CourtNumber
← 7; Booked ← TRUE ENDIF

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Question Answer Marks

1(d) IF NOT Booked AND Available8[BookTime] THEN Available8[BookTime] ← FALSE; CourtNumber

← 8; Booked ← TRUE ENDIF
IF NOT Booked OUTPUT("No court available at ", BookTime + 7)
ENDIF
IF Booked
THEN
OUTPUT ("Please enter your name")
INPUT Name
Code ← Code + 1
Correct ← "N"
WHILE Correct = "N" DO
OUTPUT ("Please enter your mobile number")
INPUT Mobile
OUTPUT ("Is Your mobile number correct Y/N? ", Mobile, " Your court number is ",
CourtNumber, " Your entry code is ", Code)
INPUT Correct
ENDWHILE
CASE CourtNumber OF
1 : Guest1[BookTime}← Name; Mobile1[BookTime] ← Mobile; Code1[BookTime] ← Code
2 : Guest2[BookTime}← Name; Mobile2[BookTime] ← Mobile; Code2[BookTime] ← Code
3 : Guest3[BookTime}← Name; Mobile3[BookTime] ← Mobile; Code3[BookTime] ← Code
4 : Guest4[BookTime}← Name; Mobile4[BookTime] ← Mobile; Code4[BookTime] ← Code
5 : Guest5[BookTime}← Name; Mobile5[BookTime] ← Mobile; Code5[BookTime] ← Code
6 : Guest6[BookTime}← Name; Mobile6[BookTime] ← Mobile; Code6[BookTime] ← Code
7 : Guest6[BookTime}← Name; Mobile7[BookTime] ← Mobile; Code7[BookTime] ← Code
8 : Guest8[BookTime}← Name; Mobile8[BookTime] ← Mobile; Code8[BookTime] ← Code
ENDCASE
NoCoutsBooked[BookTime] ← NoCoutsBooked[BookTime] - 1
ELSE
OUTPUT ("Court not booked”)
ENDIF

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Question Answer Marks

1(e) Explanation 4
Any four from
MP1 How the program totalled the number of bookings
MP2 How the program displayed the total number of bookings
MP3 How the program calculated the number of times each court was booked
MP4 How the program selected the highest value for times a court was booked
MP5 How the program displayed the court that was most booked

Programming statements must be included and must be explained.

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Question Answer Marks

Section B

2(a) Line 1 should be Counter ← 0 4

Line 3 RandNum[Counter] ← Rand(1, 100)should be RandNum[Counter] ← Rand(1, 101)
Line 4 Counter ← Counter + 2 should be Counter ← Counter + 1
Line 5 UNTIL Count <= 50 should be UNTIL Counter >= 50 // UNTIL Counter = 50

1 Counter ← 0
2 REPEAT
3 RandNum[Counter} ← Rand(1, 100)
4 Counter ← Counter + 1
5 UNTIL Counter >= 50
Or

Line 3 RandNum[Counter] should be RandNum[Count]

Line 3 Rand(1, 100)should be Rand(1, 101)
Line 4 Counter ← Counter + 2 should be Count ← Count + 1
Line 5 UNTIL Count <= 50 should be UNTIL Count >= 50 // UNTIL Count = 50

1 Count ← 0
2 REPEAT
3 RandNum[Count} ← Rand(1, 100)
4 Count ← Count + 1
5 UNTIL Count >= 50

2(b) One mark for each correct line 3

FOR Count ← 0 TO 49 // FOR Count ← 1 TO 50
RandNum[Count] ← Rand(1, 101) / Rand(0, 101)
NEXT // NEXT Count

2(c) Precondition loop // WHILE … DO … ENDWHILE 1

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Question Answer Marks

3(a)(i) one mark for sample, one mark for reason max four 4
Normal Sample any positive value with three decimal places e.g. 5.682
Reason to test that normal data is accepted and processed correctly
Erroneous Sample any value that would be rejected e.g. 5.6 or -1.345 or seven
Reason to test that erroneous data is rejected

3(a)(ii) Reason to test that 0.000 / -0.001 / highest possible non-positive is rejected and 0.001 / 0.000 / lowest positive number is 3
accepted

Sample 1 0.000
Sample 2 0.001

3(b) One mark 3

To check that values are entered as intended // to prevent incorrect values that meet the validation criteria being accepted

Two marks
Asking the user to enter the value twice and comparing the values // double entry (1) only accepting a value if both entries
are identical (1)

or

Displaying the value as it is entered (1) so the user can put right errors have been made as the value was entered (1)

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Question Answer Marks

4 One mark for each correct column 5

Counter Distinction Mark Award OUTPUT

0 0

1 1 88

2 74

3 60

4 2 90

5 3 84

6 4 87

7 5 95

8 72

9 6 84

10 66

-1 0.6 Highly Commended

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Question Answer Marks

5(a) CATEGORY – Text characters / words only used 4

PRICE – Currency, the price is in dollars / money
CODE – Text no calculations required, could be numbers or characters
STOCK – Number, comparisons and calculations may be required

5(b) One mark for correct rows Field and Table 3

One mark for correct Show row
One mark for correct Criteria row

Field: CATEGORY MANUFACTURER CODE ECONOMYRATING

Table: APPLIANCE APPLIANCE APPLIANCE APPLIANCE

Sort:

Show:    

Criteri ="A"
a:

or:

© UCLES 2021 Page 11 of 11

Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 May/June 2021
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the May/June 2021 series for most Cambridge
IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level components.

This document consists of 8 printed pages.

© UCLES 2021 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme May/June 2021
PUBLISHED

Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers.
They should be applied alongside the specific content of the mark scheme or generic level descriptors
for a question. Each question paper and mark scheme will also comply with these marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit
is given for valid answers which go beyond the scope of the syllabus and mark scheme,
referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these
features are specifically assessed by the question as indicated by the mark scheme. The
meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed
instructions or in the application of generic level descriptors.

GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question
(however; the use of the full mark range may be limited according to the quality of the candidate
responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should
not be awarded with grade thresholds or grade descriptors in mind.

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Please note the following further points:

The words in bold in the mark scheme are important text that needs to be present, or some notion
of it needs to be present. It does not have to be the exact word, but something close to the
meaning.

If a word is underlined, this exact word must be present.

A single forward slash means this is an alternative word. A double forward slash means that this is
an alternative mark point.

Ellipsis (…) on the end of one-mark point and the start of the next means that the candidate cannot
get the second mark point without being awarded the first one. If a MP has ellipsis at the beginning,
but there is no ellipsis on the MP before it, then this is just a follow-on sentence and can be
awarded without the previous mark point.

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Question Answer Marks

1(a) One mark per each correct register. 2

1 0 1 0 0 1 1 1

1 1 0 1 0 1 1 0

1(b)(i) Any one from: 1

− Both addresses can be used to identify a computer/device
− Both are unique
− Both can be represented as hexadecimal
− Both addresses do not change if IP address is static

1(b)(ii) Any two from: 2

− An IP address is assigned by the network/router/ISP, A MAC address is
assigned by the manufacturer
− An IP address can be changed (if dynamic), MAC address cannot be
changed
− IP address has 4/8 groups of values, MAC address has 6 groups/pairs of
values
− IP address is 32-bit/128-bit, MAC address is 48-bit
− IP address does not contain serial number/manufacturer number, MAC
address does
− IP(v4) address is denary and MAC address is hexadecimal

Question Answer Marks

2(a) Any three from: 3

− Keyboard
− Mouse
− Microphone
− Keypad
− Touchscreen
− Touchpad

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Question Answer Marks

2(b) One mark for each correct row. 6

USB flash
memory
Statement
HDD SSD drive
() () ()

it has no moving parts  

it is non-volatile   

it can use NAND gates to store data  

it uses magnetic properties to store data 

it has the smallest physical size 

it has the slowest read/write speeds 

2(c)(i) Any two from: 2

− It cannot be inserted incorrectly
− Supports different transmission speeds
− High speed transmission
− Automatically detected (not connected) // automatically downloads
drivers
− Powers the device (for data transfer)
− Backward compatible

2(c)(ii) − Serial 1

Question Answer Marks

3(a) One mark per each correct term in the correct order. 6
− Software
− Network
− Criteria
− Accept // reject
− Reject // accept
− Hacking

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Question Answer Marks

3(b) Any three from: 3

− Password
− Biometrics (device)
− Encryption
− Physical methods (e.g. locks)
− Two-factor authentication // Two-step verification
− Anti-viruses

Question Answer Marks

4 Any six from: 6

Phishing
− Legitimate looking email sent to user
− encourages user to click a link that directs user to a fake website
− User encouraged to enter personal details into a fake website // designed
to obtain personal details from a user

Pharming
− Malicious code/malware is downloaded/installed // software downloaded
without users' knowledge
− … that re-directs user to fake website (when legitimate URL entered)
− User encouraged to enter personal details into a fake website // designed
to obtain personal details from a user

Question Answer Marks

5 Eight from: 8
− Sensor send data/readings/signal to microprocessor
− Data is converted from analogue to digital (using ADC)
− Microprocessor compares/checks data to stored values/range of values
…
− … If data is greater than 30 / above the range microprocessor sends
signal to open window and to turn heater off
− … If data is below 25 the microprocessor sends signal to turn on heater
and to close window
− … If data is between 25 and 30 / within the range no action taken
− Actuator is used to operate heater/window
− Whole process is continuous

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Question Answer Marks

6(a) One mark per each correct logic gate, with correct input: 6

6(b) − Row 1 4
− Row 3
− Row 4
− Row 5

Question Answer Marks

7(a)(i) Four from: 4

− (Compression) algorithm is used
− No data will be removed // original file can be restored
− Example of type of algorithm that would be used e.g. RLE
− Repeated patterns in the music are identified
− … and indexed

NOTE: If another lossless method is described, marks can be awarded.

7(a)(ii) Any one from: 1

− To provide the highest quality of music file (that compression will allow)
− The user is able to listen to the original sound file
− No loss of quality for the sound file provided

7(a)(iii) Any one from: 1

− Allow for quicker streaming speed
− Would not require as much bandwidth (to stream)
− Does not need as much RAM
− Smoother listening experience // less lag
− Will not use as much of data allowance

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Question Answer Marks

7(a)(iv) Two from: 2

− Streaming speed may be slower
− … and may affect listening experience // buffering may occur
− User may need more bandwidth to stream
− … that could be more expensive
− It would be a larger file size
− … so may take longer to upload
− … so will take up more storage space …
− … on webserver

7(b) Any four from: 4

− Browser sends URL to DNS
− … using HTTP/HTTPS
− IP address is found on DNS
− DNS returns IP address to the browser
− Browser sends request to web server/IP address
− Web server sends web pages back to browser
− Browser interprets/renders the HTML (to display web pages)
− Security certificates exchanged

7(c) Two from: 2

− Web server has been flooded with traffic // web server has been sent
many requests at once
− … so, server is brought to a halt / crashes

Question Answer Marks

8(a) − Odd 4
− Odd
− Even
− Even

8(b) Any one from: 1

− there is a transposition of bits
− it does not check the order of the bits (just the sum of 1s/0s)
− even number of bits change
− incorrect bits still add up to correct parity

8(c)(i) Four from: 4

− Multiple bits are sent at the same time
− Uses multiple wires
− Data is sent in both directions …
− … but only one direction at a time

8(c)(ii) Any two from: 2

− Bits may arrive skewed
− More expensive to setup/manufacture/purchase cable
− Limited distance
− More prone to interference/error

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 May/June 2021
MARK SCHEME
Maximum Mark: 50

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the May/June 2021 series for most Cambridge
IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level components.

This document consists of 11 printed pages.

© UCLES 2021 [Turn over

0478/21 Cambridge IGCSE – Mark Scheme May/June 2021
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

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0478/21 Cambridge IGCSE – Mark Scheme May/June 2021
PUBLISHED
Please note the following further points:

The words in bold in the mark scheme are important text that needs to be present, or some notion of it needs to be present. It does not have to
be the exact word, but something close to the meaning.

If a word is underlined, this exact word must be present.

A single forward slash means this is an alternative word. A double forward slash means that this is an alternative mark point.

Ellipsis (…) on the end of one-mark point and the start of the next means that the candidate cannot get the second mark point without being
awarded the first one. If a MP has ellipsis at the beginning, but there is no ellipsis on the MP before it, then this is just a follow-on sentence and
can be awarded without the previous mark point.

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Question Answer Marks

Section A

1(a)(i) Many correct answers. They must be meaningful and related to Task 1. The names are examples only. 3

One mark per mark point

• Constant MaxCandidates
• Value 4
• Use The value of the maximum number of candidates for the election

1(a)(ii) Many correct answers. They must be meaningful and related to Task 1. The names are examples only. 4

One mark per mark point

• Variable NumberCandidates
• Use Storing the number of candidates in the election (for a tutor group)

• Array CandidateNames
• Use Storing the names of the candidates for the election

1(b) One mark per mark point (Max 4) 4

MP1 Change the value of the MaxCandidates constant/variable to 8
MP2 Change the input message to state the maximum number of candidates is 8 …
MP3 …how your program changed the input message
MP4 Change the loop limit to up to 8 …
MP5 …how your program changed the loop limit
MP6 Change the validation to allow input up to 8 …
MP7 …how your program changed its validation check
MP8 Change the array size(s) to ensure sufficient capacity to store up to 8 names …
MP9 …how your program changed the array sizes
MP10 Change the counters to ensure votes can be counted for up to 8 candidates …
MP11 …how your program changed its counters

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Question Answer Marks

1(c) Any five from: 5

MP1 Input with message to enter unique voter number
MP2 Validation of (unique) voter number entered e.g. length check/type check/range check
MP3 Attempt to check if voter number input is in list of possible voters
MP4 Attempt to check if they have already voted
MP5 If voter has already voted, message to warn them they can’t vote
MP6 Attempt at preventing them from voting
MP7 Store voter number in a suitable data structure

Example answer
OUTPUT "Please enter your unique voter number"
INPUT UniqueVoterNumber
FoundFlag ← False
AllNumbersChecked ← False
Counter ← 0
WHILE FoundFlag = False AND AllNumbersChecked = False
IF StudentNumbers[Counter] = ""
THEN
AllNumbersChecked = True
StudentNumbers[Counter] ← UniqueVoterNumber
ELSE
IF UniqueVoterNumber = StudentNumbers[Counter]
THEN
FoundFlag = True
PRINT “Sorry, you have already voted”
ELSE
Counter = Counter + 1
ENDIF
ENDIF
ENDWHILE
IF FoundFlag = False
THEN
OUTPUT "Please enter the code of your chosen candidate"
INPUT Vote
ENDIF

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Question Answer Marks

1(d) Explanation of how the program does the following: 4

Any four from:
MP1 Find out how many votes in total (for all candidates) were cast in the election.
MP2 For each candidate
MP3 … calculate the percentage of votes
MP4 … excluding abstentions.
MP5 Display the name of each candidate, the number of votes and the percentage of votes they received with
appropriate messages.
MP6 Display the number of votes cast and the number of abstentions with appropriate message.

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Question Answer Marks

Section B

2 One mark per correct column 3

Statement Validation Verification Both

Entering the data twice to check if both entries are the same. 

Automatically checking that only numeric data has been entered. 

Checking data entered into a computer system before it is stored or


processed.

Visually checking that no errors have been introduced during data


entry.

Question Answer Marks

3 One mark per bullet point 6

37
• Data type name Integer
• Data type description (Any) whole number

Cambridge2021
• Data type name String
• Data type description A group of characters/text

47.86
• Data type name Real
• Data type description (Any real) number that could be a whole number or a fraction

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Question Answer Marks

4(a) One mark per mark point (Max 3) 3

MP1 Marks input are stored in the array Score[]
MP2 Marks are checked against a range of boundaries // allow example
MP3 … and a matching grade is assigned to each mark that has been input
MP4 … then stored in the array Grade[]…
MP5 … at the same index as the mark input
MP6 The algorithm finishes after 30 marks have been input // allows 30 scores to be entered

4(b) One mark per mark point (Max 3) 3

MP1 Correct loop, including counter if not a FOR loop
MP2 Correct output of Score[]
MP3 Correct output of Grade[]
MP4 Suitable messages/text in output for both arrays

Example answers
Count ← 0
REPEAT
PRINT "Student: ", Count, " Mark: ", Score[Count], " Grade: ",Grade[Count]
Count ← Count + 1
UNTIL Count = 30

Count ← 0
WHILE Count < 30 DO
PRINT "Student: ", Count, " Mark: ", Score[Count], " Grade: ",Grade[Count]
Count ← Count + 1
ENDWHILE

FOR Count ← 0 TO 29
PRINT "Student: ", Count, " Mark: ", Score[Count], " Grade: ", Grade[Count]
NEXT

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Question Answer Marks

4(c) Any three correct statements (Max 3) e.g. 3

MP1 Add an input facility to allow teachers to enter the class size
MP2 Add a variable to store the input class size
MP3 Use the class size variable as the terminating condition for the loop
MP4 Make sure the arrays are sufficiently large to accommodate the largest possible class size

Question Answer Marks

5(a) One mark for each correct column (Max 4) 4

Value Diff1 Diff2 OUTPUT

50 50 0 Accept: Extreme

75 25 25 Accept: Normal

99 1 49 Accept: Normal

28 Reject: Abnormal

82 18 32 Accept: Normal

150 Reject: Abnormal

–1

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Question Answer Marks

5(b) One mark per bullet point (Max 2) 2

• To output the type of test data
• … by performing a range check //… by checking if numbers are within the range 50 and 100 (inclusive) (or not).

Question Answer Marks

6(a) The data in the ID column/field is unique/not repeated in each row/record 1

6(b) 18 1

6(c) 4
Field: ID GenreName Overdue

Table: GENRE GENRE GENRE

Sort: Descending

Show:     

Criteria: >0

or:

One mark for the correct fields present and correctly named
One mark for correct table name and show box in all columns
One mark for correct sorting
One mark for correct search criterion

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 October/November 2020
MARK SCHEME
Maximum Mark: 75

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2020 series for most
Cambridge IGCSE™, Cambridge International A and AS Level and Cambridge Pre-U components, and some
Cambridge O Level components.

This document consists of 11 printed pages.

© UCLES 2020 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme October/November 2020
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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PUBLISHED
GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

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Question Answer Marks

1 One mark per each correct row: 6

Input Output Storage

Device
() () ()

Keyboard 

Sensor 

3D Cutter 

2D Scanner 

Microphone 

Hard disk drive (HDD) 

Question Answer Marks

2(a) One mark for each correct binary conversion 6

One mark for each correct denary conversion

Hexadecimal 12-bit binary value Denary value

ticket number

028 0000 0010 1000 40

1A9 0001 1010 1001 425

20C 0010 0000 1100 524

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Question Answer Marks

2(b) Seven from: 7

− Camera captures code // Laser/light shone on code
− Black squares reflect different light to white
− Corner squares are used for alignment
− Pattern converted to digital data // by example
− (Digital) data sent to microprocessor
− There is a database of valid QR codes
− Data compared to stored values/valid QR codes …
− … If data matches entry is granted is raised
− … If data matches count is incremented
− … If data does not match, entry is denied

Question Answer Marks

3(a) − Handshake 2
− Record

3(b) 5
− Web server
− Certificate
− Authentic
− Browser
− Signal

3(c) Any one from: 1

− SSL
− HTTPS

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Question Answer Marks

4(a) 4

One mark for each correct gate with correct input

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Question Answer Marks

4(b) Four marks for 8 correct outputs 4

Three marks for 6/7 correct outputs
Two marks for 4/5 correct outputs
One mark for 2/3 correct outputs

A B C Working space X

0 0 0 1

0 0 1 0

0 1 0 0

0 1 1 0

1 0 0 1

1 0 1 0

1 1 0 1

1 1 1 1

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Question Answer Marks

4(c) One mark for the correct gate and one mark for the correct truth table 4

− AND
A B X

0 0 0

0 1 0

1 0 0

1 1 1

− XOR
A B X

0 0 0

0 1 1

1 0 1

1 1 0

Question Answer Marks

5(a)(i) − Two valid examples of Structure e.g. where text is placed, margins of page 2

5(a)(ii) − Two valid examples of Presentation e.g. font size, font colour 2

5(b) − Firewall 2
− Proxy server

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Question Answer Marks

6(a)(i) − Uses multiple wires 2

− Sends multiple bits of data at a time

6(a)(ii) − Faster transmission speed 1

6(b)(i) − Control (bus) 1

6(b)(ii) − Accumulator (ACC) 1

6(b)(iii) 4
True False
Statement
() ()

Data and instructions are stored in the same memory unit 

The control unit manages operations within the CPU 

Data and instructions can be fetched into the CPU at the same time 

The control unit is responsible for decoding an instruction 

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Question Answer Marks

7 Four from (Max two per format): 4

MIDI
− Musical Instrument Digital Interface (file)
− Stores a set of commands/instructions (for how the sound should be played)
− Does not store the actual sounds
− Data in the file has been recorded using digital instruments // produced by synthesizer
− Specifies pitch of the note // specifies the note to be played
− Specifies when each note plays and stops playing // Specifies key on/off
− Specifies duration of the note
− Specifies volume of the note
− Specifies the tempo
− Specifies the type of instrument
− Individual notes can be edited
MP3
− MP3 is a format for digital audio
− MP3 is an actual recording of the sound
− MP3 is a (lossy) compression format
− Recorded using a microphone

Question Answer Marks

8(a) Any three from: 3

− Light emitting diodes (technology)
− The display is made up of pixels
− … that are arranged together as a matrix
− … each is formed of three LEDs/filters
− Shades of colour are achieved by mixing red, blue and green
− The screen can be back-lit/edge-lit

NOTE: Use of liquid crystals with LED technology can also be awarded

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Question Answer Marks

8(b) Any three from: 3

− Energy efficient // low power consumption
− Long lasting // longevity
− Focussed beam // less light strays from beam
− Brighter/vivid colours
− High resolution
− No flicker
− Display is thinner
− Mercury free technology // environmentally friendly
− Fewer pixel failure
− Increased viewing in sunlight

8(c) − LCD 1

Question Answer Marks

9(a) − 1 4
− 0
− 0
− 0

9(b) Two from: 2

− Checksum
− Automatic repeat request // ARQ

9(c) Any four from: 4

− Data is input with check digit
− A calculation is performed on the (inputted) data // by example
− The calculated digit is compared to a stored value
− If it matches, the data entered is correct
− If it does not match, the data entered is incorrect

© UCLES 2020 Page 11 of 11

Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 October/November 2020
MARK SCHEME
Maximum Mark: 50

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2020 series for most
Cambridge IGCSE™, Cambridge International A and AS Level and Cambridge Pre-U components, and some
Cambridge O Level components.

This document consists of 6 printed pages.

© UCLES 2020 [Turn over

0478/21 Cambridge IGCSE – Mark Scheme October/November
PUBLISHED 2020

Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers.
They should be applied alongside the specific content of the mark scheme or generic level descriptors
for a question. Each question paper and mark scheme will also comply with these marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit
is given for valid answers which go beyond the scope of the syllabus and mark scheme,
referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these
features are specifically assessed by the question as indicated by the mark scheme. The
meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed
instructions or in the application of generic level descriptors.

GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question
(however; the use of the full mark range may be limited according to the quality of the candidate
responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should
not be awarded with grade thresholds or grade descriptors in mind.

© UCLES 2020 Page 2 of 6

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PUBLISHED 2020

Question Answer Marks

Section A

1(a) For one array 3

One mark for naming of an array with a suitable data type and one mark for
its use

Array yearsWithoutClaim
Data type integer
Use to store the % discount

Many correct answers, this is an example only.

1(b) For each validation check 4

One mark for identification of a check and one mark for the reason max 4

Check presence check

Reason need to enter age to calculate price

Check type check

Reason need to check age is a positive integer

Many correct answers, these are examples only.

1(c) Any six from: 6

MP1 Input with prompt if new customer
MP2 Check age greater than or equal 26
MP3 Check age less than or equal 70
MP4 Check number of years without a claim greater than or equal to 2 …
MP5 … discount 10%
MP6 Otherwise discount 0%
MP7 Calculate new price and value of extra discount
MP8 Output new price and value of extra discount, with suitable message

Sample answer
PRINT "Are you a new customer Y/N?"
INPUT new
discount ← 0
IF new = "Y" DO
IF age >= 26 AND age <= 70
THEN
IF yearsWithoutClaim >=2
THEN
discount ← price * 0.1
price ← price * 0.9
ENDIF
ENDIF
PRINT "New price", price
PRINT "Extra discount for new customer", discount
ENDIF

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Question Answer Marks

1(d)(i) Explanation 4
Any four from:
MP1 Provide a prompt and input to check if additional driver required
MP2 Check response with IF/REPEAT/WHILE/CASE statement for yes
MP3 … input age of additional driver
MP4 … Use of IF / REPEAT etc. to validate age
MP5 … use the age input to find / look up appropriate price increase
MP6 … description of how the price to pay now is calculated
MP7 … description of how the price to pay now is displayed including the use
of a suitable message
For no
MP8 … no output required or suitable message output

Programming statements can be used but must be explained.

1(d)(ii) Description 3
Any three from:
MP1 Use a variable (quotes) to keep a running total of the number of quotes
provided
MP2 Ask, using prompt with input, customers if they are going to purchase
the insurance
MP3 Use another variable (policies) to keep a running total of the number of
insurances bought / not bought
MP4 Use these to calculate the percentage policies/quotes*100

Question Answer Marks

Section B

2 One mark for description of variable 4

One mark for description of constant
One mark for inclusion of an example variable
One mark for inclusion of an example constant

Example answer:
A value that can change during the execution of a program
A named value that cannot change during the execution of a program
Variable example - using a counter for example counter ← counter + 1
Constant example – a static value that can be used for checking for example
< maxAge

Question Answer Marks

3(a) Line 1/2/3/4/8/9 4

Lines 5–11
Line 9
Line 8

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Question Answer Marks

3(b) One mark for error and correction 4

Line 1 TotalWeight ← 0
Line 10 move OUTPUT "Number of bags in the load is ",
BagCount to end / after line 11
Line 11 UNTIL TotalWeight > MaxWeight OR BagCount >= MaxBag
Line 12 OUTPUT "Total weight of the load is ", TotalWeight

3(c) Any four from: 4

After line 11
Divide TotalWeight by
… BagCount
Assign a new variable AverageWeight ← TotalWeight / BagCount
Output the result OUTPUT AverageWeight
With a message "Average weight of a bag of firewood is "

Question Answer Marks

4(a) One mark for correct input columns (V, W, X, Y, Z) 4

One mark for correct calculation column A
One mark for correct calculation column B
One mark for correct output column

V W X Y Z A B OUTPUT

5 4 6 2 1 56 1 Valid

9 3 2 1 6 40 7 Invalid

7 6 1 5 1 61 6 Invalid

0 0 0 0 0

4(b) • (Use first four digits input to) calculate a check digit 2
• Check if the check digit input is valid

Question Answer Marks

5(a) 6 fields 2
9 records

5(b) Either mark by row or by column but not both 2

One each correct row or one mark for each correct column max two
Koala3 Australia
SkyKing Europe

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Question Answer Marks

5(c) 4
Field: Airline name Number of Head office
countries

Table: AIRLINE AIRLINE AIRLINE

Sort:

Show:    

Criteria: >4 ="Asia"

or: >4 ="Africa"

one mark for correct fields and correct table names, must have the three
columns required, ignore another column provided the show row is not ticked
and there are no criteria set for that column
one mark for correct show row
one mark for correct number of countries criteria
one mark for correct head office criteria

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/11

Paper 1 May/June 2020
MARK SCHEME
Maximum Mark: 75

Published

Students did not sit exam papers in the June 2020 series due to the Covid-19 global pandemic.

This mark scheme is published to support teachers and students and should be read together with the
question paper. It shows the requirements of the exam. The answer column of the mark scheme shows the
proposed basis on which Examiners would award marks for this exam. Where appropriate, this column also
provides the most likely acceptable alternative responses expected from students. Examiners usually review
the mark scheme after they have seen student responses and update the mark scheme if appropriate. In the
June series, Examiners were unable to consider the acceptability of alternative responses, as there were no
student responses to consider.

Mark schemes should usually be read together with the Principal Examiner Report for Teachers. However,
because students did not sit exam papers, there is no Principal Examiner Report for Teachers for the June
2020 series.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the June 2020 series for most Cambridge
IGCSE™ and Cambridge International A & AS Level components, and some Cambridge O Level
components.

This document consists of 11 printed pages.

© UCLES 2020 [Turn over

0478/11 Cambridge IGCSE – Mark Scheme May/June 2020
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

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Question Answer Marks

1(a) Any one from: 1

− Microphone
− Touchscreen
− Camera
− Button

1(b) Any two from: 2

− Speaker
− Touchscreen
− Light/flash

1(c)(i) Any one from: 1

− Media access control
− Unique address given to each device

1(c)(ii) Any three from: 3

− Uses hexadecimal values
− Normally 48/64 bits in length (accept any other reasonable value)
− First half is manufacturer number/code/ID
− Second half is serial number

1(d) − It needs RAM to store the data and programs currently in use 2
− It needs ROM to permanently store the boot up instructions

1(e)(i) Any two from: 2

− Fingerprint scanner
− Voice recognition
− Retina/iris recognition
− Facial recognition

1(e)(ii) Any two from: 2

− Adds extra level of security
− Biometric device requires properties unique to individual
− Allows quicker access as no need to input password // don’t need to remember password

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Question Answer Marks

2(a) 5

1 mark for each correct gate.

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Question Answer Marks

2(b) 4
A B C Working space X

0 0 0 1

0 0 1 0

0 1 0 1

0 1 1 0

1 0 0 1

1 0 1 0

1 1 0 1

1 1 1 0

4 marks for 8 correct outputs

3 marks for 6 or 7 correct outputs
2 marks for 4 or 5 correct outputs
1 mark for 2 or 3 correct outputs

Question Answer Marks

3(a) Any three from: 3

− It is a universal standard
− It can’t be inserted the wrong way around
− Supports different transmission speeds
− Automatically detects if correct driver installed
− It will charge the mobile device at the same time

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Question Answer Marks

3(b) − Serial 1

3(c) − A compression algorithm is used 4

− No data is removed in the compression process
− An index/dictionary of pixels is created
− The number of times a pixel is repeated in a row is stored

Question Answer Marks

4(a) Any two from: 2

− They both calculate a value from the data
− They both append the calculated value to the data
− They both recalculate the value
− … They both report an error if they don’t match

4(b) One mark for method, three marks for description: 4

Automatic Repeat reQuest
− Uses acknowledgement / request and time-out
− Error control protocol
− Check performed on receiving data // error is detected by e.g. parity check, check sum
− If error detected, request is sent to resend data // negative acknowledgement is used
− Resend request is repeated till data is sent correctly / requests timeout / limit is reached
− Send acknowledgement that data is received // positive acknowledgement is used
− If acknowledgement not received in set time data is resent

Parity Check
− A parity bit is added (to the parity byte)
− Counts / checks number of 1’s
− Can be even or odd
− If parity is incorrect, error is detected

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Question Answer Marks

5 6
CPU Not a CPU
Component component component
() ()

Arithmetic logic unit (ALU) 

Hard disk drive (HDD) 

Memory address register (MAR) 

Random access memory (RAM) 

Solid state drive (SSD) 

Control unit (CU) 

One mark per each correct row

Question Answer Marks

6 4
Sensor Scenario

Pressure / motion / infra-red Detecting when a person is approaching an automatic

door system

pH / light Monitoring the pollution level in a river

Temperature Checking if a tropical aquarium is 25 degrees Celsius

Magnetic field / pressure / motion / infra-red Counting the number of cars that cross a bridge

One mark per each correct sensor (each sensor must be different)

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Question Answer Marks

7(a)(i) Any four from: 4

− Keylogger is downloaded without knowledge (by example)
− Keylogger records key presses
− Data is relayed back to third party
− Data is analysed // Patterns in data could reveal log-in details …
− … details can then be used to log into the account

7(a)(ii) Any one from: 1

− Use drop-down boxes for password
− Two-step verification (by example)
− Partial password requests
− Onscreen / virtual keyboard

7(b)(i) Any one from: 1

− Look for locked padlock / green padlock
− Check for https

7(b)(ii) Any four from: 4

− requests web server to identify itself // request to view the (SSL) certificate
− receives a copy of the (SSL) certificate, sent from the webserver
− checks if (SSL) certificate is authentic/trustworthy
− sends signal back to webserver that the certificate is authentic/trustworthy

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Question Answer Marks

8(a) − Interrupt 1

8(b) One mark for benefit, two marks for drawbacks 3

Benefit:
− Printing may be higher quality
− Can use larger paper sizes
− Can print onto different media
− No warm-up time

Drawbacks:
− Printing will be slower
− Ink is more expensive per page
− Ink can be smeared // ink is not smudge proof

8(c) 4
Inkjet Laser
Statement
() ()

Uses a rotating drum to transfer the image to the paper 

Uses powdered toner 

Uses nozzles to spray droplets on to the paper 

Uses a print head mechanism that moves side to side 

One mark per each correct row

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Question Answer Marks

9(a) Any three from: 3

− Closer to/is machine code
− May use mnemonics
− May need an assembler to be translated
− One line of code represents a single instruction
− Machine dependent
− Have direct access to memory locations/registers

9(b) − Assembly code 2

− Machine code

9(c) Any one from: 1

− It is more difficult to understand
− Error prone
− Have to manipulate memory locations
− Machine dependent

9(d)(i) − 10110100 2
− 11001001

9(d)(ii) − 000011111010 (must have leading zeros) 1

9(d)(iii) − 93 2
− 1D

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Cambridge IGCSE™

COMPUTER SCIENCE 0478/21

Paper 2 May/June 2020
MARK SCHEME
Maximum Mark: 50

Published

Students did not sit exam papers in the June 2020 series due to the Covid-19 global pandemic.

This mark scheme is published to support teachers and students and should be read together with the
question paper. It shows the requirements of the exam. The answer column of the mark scheme shows the
proposed basis on which Examiners would award marks for this exam. Where appropriate, this column also
provides the most likely acceptable alternative responses expected from students. Examiners usually review
the mark scheme after they have seen student responses and update the mark scheme if appropriate. In the
June series, Examiners were unable to consider the acceptability of alternative responses, as there were no
student responses to consider.

Mark schemes should usually be read together with the Principal Examiner Report for Teachers. However,
because students did not sit exam papers, there is no Principal Examiner Report for Teachers for the June
2020 series.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the June 2020 series for most Cambridge
IGCSE™ and Cambridge International A & AS Level components, and some Cambridge O Level
components.

This document consists of 10 printed pages.

© UCLES 2020 [Turn over

0478/21 Cambridge IGCSE – Mark Scheme May/June 2020
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the
scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

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Question Answer Marks

1(a)(i) Any meaningful array related to Task 1 – one mark (max two) e.g. 4
ItemCode
Description

Correct purpose for each array related to Task 1 – one mark (max two) e.g.
…to store the item codes
…to store the descriptions of the items for sale

1(a)(ii) Any meaningful variable related to Task 1 – one mark (max two) e.g. 4
PurchaseItem
TotalPrice

Correct purpose for each variable related to Task 1 - one mark (max two) e.g.
… to allow input of an item/code for purchase
… to store/calculate the total price of the transaction

1(b) Any one correct statement e.g. 2

• The Code data is made up of letters/alphabetic characters/not numbers
• Real data must have numerical value/would not be used in calculations

One mark for:

• String

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Question Answer Marks

1(c) Any five from 5

• Input with message to allow choice of mobile device
• Attempt to validate input to check for valid item code
• Accurate validation of input to check for valid item code
• Determination of whether device is phone or tablet
• Restriction to only allow input for SIM card required if mobile device is a phone
• Input with message to find out if a SIM card is required

Example answer
OUTPUT "Which type of phone or tablet would you like? Input the Item Code"
DeviceFlag ← False
WHILE DeviceFlag = False
INPUT DeviceCode
Count ← 0
WHILE Count<10 DO
IF DeviceCode = ItemCode[Count]
THEN
IF Count < 6
THEN
DeviceType ← "Phone"
ELSE
DeviceType ← "Tablet"
ENDIF
DeviceFlag ← True
Count ← 10
ENDIF
Count ← Count + 1
ENDWHILE
IF DeviceFlag = False
THEN

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Question Answer Marks

1(c) OUTPUT "Your code doesn’t exist, please try again"

ENDIF
ENDWHILE
IF DeviceType ← "Phone"
THEN
OUTPUT "Would you like a SIM Card? (Answer Y or N)"
INPUT SimRequired
ENDIF

1(d) Any five from 5

• Explanation of finding if more than one device is purchased
• Explanation of application of device discount
• Explanation of calculating the discount(s) and finding the new price
• Explanation of outputting new total
• Explanation of outputting amount saved
• Explanation of messages used

Question Answer Marks

2 2
True False
Statement
() ()

A structure diagram is a piece of code that is available throughout the structure of a program. 

A structure diagram shows the hierarchy of a system. 

A structure diagram is another name for an array. 

A structure diagram shows the relationship between different components of a system. 

Two marks for four correct rows.

One mark for three correct rows.

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Question Answer Marks

3(a) One mark for each correct validation check (max two) 4
• Range
• Length
• Type
• Check Digit

One mark for each correct related purpose (max two) e.g.
• To make sure the data entered falls within a specific set of values
• To make sure the data entered is no longer than specified
• To make sure the data entered follows rules related to whether it is numbers of letters
• To make sure an identification code entered is genuine or possible

3(b) One mark for correct verification check (max one) 1

• Double (data) entry
• Visual check

3(c) Any two correct statements (max two) e.g. 2

• Validation checks if the data entered is possible/it cannot check if data has been entered correctly.
• Verification checks if the data entered matches the data submitted for entry/ it does not check if data matches set
criteria.

Question Answer Marks

4(a) Any two correct statements (max two) e.g. 2

• The value of the variable Count begins as 0 …
• … and is incremented by 1 before it is tested by the loop condition
• Count will never be 0 at the end of the loop

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Question Answer Marks

4(b) 4
Count ← 0
REPEAT
INPUT Number
IF Number >= 100
THEN
Values[Count] ← Number
ENDIF
Count ← Count + 1
UNTIL Count = 50

One mark – separate INPUT statement

One mark – IF statement attempted
One mark – IF statement completely correct
One mark – termination of loop updated

4(c) Any two correct statements (max two) e.g. 2

• Alter the IFstatement/add a second IF statement/comparison that’s already there …
• … so that additional criteria set an upper limit of <=200

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Question Answer Marks

5(a) 4
Value Calc1 Calc2 OUTPUT

50 25 16

33 16 11

18 9 6 18

15 7 5

30 15 10 30

-1

One mark for each correct column (max four)

5(b) Any two correct statements e.g. 2

• The program outputs a value
• That is divisible by 6 // 2 and 3

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Question Answer Marks

6(a) To uniquely identify a product (in TOOLS) 1

6(b) HS50 Hose (50 metres) 60 3

GFLG Garden Fork 50
LMPT Lawn Mower (Petrol) 25

One mark for correct data

One mark for correct format
One mark for data in correct order

6(c) 3
Field: Code Description Quantity_Stock

Table: TOOLS TOOLS TOOLS

Sort: Ascending

Show:     

Criteria: <25

or:

One mark for each completely correct column (max three)

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