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0% found this document useful (0 votes)
64 views100 pagesIntroducing Statistics
TR Jain book pdf on statistics
Uploaded by
guptaanandita516Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF or read online on Scribd
/ 100
“pness a
ar panel “the problene
s lik a household, a
in or an Use
peconomics
telated
try. These issues
‘Oo gnascenising
ay These issues or problems
goals of social welfare or
tudied and addressed keeping in mind the
are st
‘collective welfare)
2. What is Statistics?
Even to a layman this shou
to define Statistics, we can Exped
id not be a difficult question. If asked
ta layman to say that Statistics
is something information. Yes, it is
a 7 g ¢mation-or quantification
of the facts and findings. But, how mG we get quantitative
information? There must be a system, method or techniqu
collect quantitative information. sais
like a store of quantitaeve
> © Concept of Economics and Significance of Statistics in Economics Qf
sbenmeNeinformation a needs to be classified, tabulated or it
needs to be s lly presented. One must learn the system
of presentation and ation of data. Also, there must be a
set of methods and techniques to condense the data. May be, we
find averages or percentages. And above all, there must be a set
of methods or techniques on the analysis and interpretation of
quantitative information. A student of Economics has to study
all these methods and techniques to understand and master the
subject matter of Statistics.
Thu:
inlike a layman, a student of Economics cannot relax taking
Statistics just as a pool of quantitative information. Instead he is
also to look into the methods or techniques relating to its collection,
classification, presentation, analysis as well as interpretation.
In view of such a vastness of the subject matter, Statistics is defined
both in singular sense and plural sense, as under:
Sratistics—A PLURAL Noun
tatistics concerning Public Expenditure, | V \g
etc. However, any numerical information is not Statistics. :
Example: Ram gets € 100 per month as pocket allowance is not remanent
Statistics (it is neither an aggrégate nor an average) whereas
average pocket allowance of the students of Class X is 100 per
f
\
month, or there are 80 students in Class XI compared to just 8in |
Class XII of your school are Statistics. \ i
1
\
t
population growth
in india) GSE >
The following table showsa set of data which is Statistics, and another me
like the
set which is not Statistics. The figures used are hypothetical. \ gar
\ inverse relationship
Dataiwhich/are not Statisti {Data which are Statistics 25)| | between price ofa
) A cow has 4 legs. (i) Average height of the 26-plus| | commodity and its
~-male_people- in. India-is 6 feet.| | demand)
compared to 5 feet in Nepal.
(i) Ram has 200 rupees in his pocket. | (i) Birth rate in India is 18 per| | Donottake statistics
thousand compared to 8 per| {| aSsome quantitative
thousand in USA. \ information relating to
Nee
(iii) A young lady was run over by | (iii) Over the past 10 years, India has}! SO ee vu
a speeding truck at 100 km per won 60 test matches in cricket} | "Ve
hour. and lost 50. { three
ig by doing cameraman?
Definition is is how Sta is defined by diffe,
In its plural sense, this IS 2
authors: 5 numerical statements of. facts in any departmery ‘
" a oa in relation (0 each other. Cane
gu ny M is we mean quantitative data affected to a marked ie
Somme a ee ini of causes.” Yule and Kea
oe ‘aires or Characteristics of eS
in the Plural Sense OF as Numerical Data
Main characteristics of Statistics in terms of numerical data are as
‘Mai
pipe ate of Facts: A single number does not constitute
fee. No conclusion can be drawn from it»kiisiealyaie,
‘or example, if it is stated that there are 1,000 students in
r college, then it has no statistical ‘significance. But if it
js stated that there are 300 students in arts faculty, 400 in
aQ commerce faculty and 300 in science faculty in our college,
it. makes statistical sense as this data conveys statistical
information) Similarly, if it is stated that population of India
is 121 crore or that the value of total exports from India is
% 11,66,439 crore, then these aggregate of facts will be termed
as Statistics. It can, therefore, be concluded ‘All Statistics are
ressed in numbers but all numbers are not Statistics’.
jumerically Expressed: Statistics are expressed in terms
of numbers. uitative 6 ‘small?o ‘ich’ or
{Statist ‘or Instance, to say, Irfan
Fithehon ein achin is short, has no statistical sense.
eo ane ae is Seated that height of Irfan Pathan is 6 ft and
iiterieals il a eeachn is 5 ft and 4 - inches, then these
gf stecteay " ¢ called Statistics)
byany sit : Seay of Causés( Statistics are not affected
2 AB 3 ut are influenced by many factor’
For instance,
O perce; f
Nt rise in pri 1 ance
. Tices
Brices may have been due ta coveral causes. ron cua dt teak th ee in Economics a
errr
vantitative and Qualitative
| This is related to the
1 distinction between
| quantitative variables
‘h numericals alone will
is are yore ‘lated and so com) parable)
| For example, if it is stated “Ram is 40 years old, Mohan is
5 ft tall, Sohan has 60 kg of weight’, then these numbers
will not be called Statistics, as they are not mutually related
t
1
'
: 4
{income in india was (say)
| | %4,000 per month, per
nor subject to comparison. However, if the age, height and "
y
+ capita expenditure was
weight of all the three are inter-related, themrthe same will be _ | (629) 3.000 per month,
Copsidered as Statistics.)
=
1 and net investment (or
- { capital formation) was
re-determined Purpose: (Statistics are collected with some
pre-determined objective. oll
\ (say) 10,000 crore in 4
jation Collected without
: fh | theyear 2003 04/0
; ion ia valve and, | a
paseaties pertaining to the farmers of a village
1s collected, there must be some pre-determined objecti
Whether the Statistics are collected for the purpose o!
knowing their economic position, or distribution of land
among them or their total population, or for any, other
pose, all these objectives must be pre-determined)
phate or- Estimated:
(Gasiiemnyaremmie
by enumeration or the same be estimated W/E fild? of | qualitative characteristics
ve tori is’ vast, “ it jonijimaysibe | of the objects. These
‘ canbe ranked orrated ©
addressed by the Prime Minister in Dethi and 2 lakhs in| 2600¥er good. or
Mumbai. These Statistics are based on estimation {ASfagainst | y at
pannieislimi greiner ery
\
t
1
1
it
for example,
‘them ranl Sete.
fationmethiod is | Alaiohdalgare calles
by enumeration
whether 20 students are
ative data) Briefly,
esent in the class or 10 workers 1 While quanifative data
ae working in the Ber)
\ refer to quantitative
. o owe qualitative
Collected in a Systematic Manner: Gaatistis should be | Vatables, cual
collected in a systema i
1 data refer to qualitative
sscollectingsthemssa | attibutes ofthe differen
tic
spared]
\ | objects.
cted:inhaphazar inner)or instance, data “~~
regarding the marks secured by the students of a college
without any reference to the class, subject, examination or
maximum marks, etc., will lead to no conclusion. ara Concept of Economies and Significance oF Statistics in Economies
juded th
In
Learning by doing
i Write five examples cach of ‘quantitative variables’ and ‘qualitatirg
Fvariables’, Quantitative variables should be’ the well known terms vy
like production of wheat in India over the last 10 years.
Econom:
A SinGuLAR NOUN
singular sense, Stat $s means science of Statistics o;
v4] statistical methods. It refers to techniques or methods relating
collection, classification, presentation, analysis and interpretation
of quantitative data.
Focus of the Study Definition
Q “Statistics may be defined as the collection, presentation, analysis and
: ee interpretation of numerical data." | —Croxton and Cowden
1 study forthe students of
1 Class Xl, You are to learn
| and understand how to
| collect data, organise
+ data, present data as well
1 as analyse and interpret
| data.
Q “Statistics is the science which deals with the collection, classification
and tabulation of numerical facts as a basis for the explanation
description and comparison of phenomena.” —Lovitt
>
STAGES OF STATISTICAL STUDY if
Studying Statistics as a singular noun implies the knowledge of
ical study. These stages are:
various stages of statis
f Interpretation
of Data
ey. Analysis
peed Dat
Presentation ote
of Data
Stage Ill RET Cae Concept of Economics and Siniicance of Stateticsn Econorics EA
Soest pee hoa
Suatisticar Toois
ach stage of the al study involves the use of certain
ndard techniques or methods. These techniques or methods
e
She. are called statistical tools. Thus, there are statistical tools used for
Re rr the collection of like the ‘Sample’ and ‘Census’ techniques.
=O Array of data and tally bars are the standard techniques used for
ion organisation of data. Tables, graphs and diagrams are the well-
known statistical tools for the presentation of data. =
Averages and percentages are the commonly used techniques
a4 for the analysis of data. Interpretation of data is often done in
terms of the magnitude of averages, percentages or coefficients of
correlation/regression. The following table gives an overall view
of the various stages of statistical study and the related sets of
a statistical tools.
: Stages of Statistical Study and the Related Statistical Tools
"Statistical Tools i
Census or Sample Techniques
Statistical Study
Collection of Data
fsue 77 Organisation of Data. | Array of Data and Tally Bars
pose 11 | Presentation of Data_ | Tables, Graphs and Diagrams
tage IV | Analysis of Data Percentages, Averages, tion
= es and Regression C Coelficients
ges
Stage V_| Interpretation of Data | Magnitude-of Percentages,
5 adh the Degree 6f Relations
between different economic variables
iprehensively Sane in the relevant: chapters of the to
ei stuc
oot expected to mug up these terms at this stage of
8. Scope of Statistics |)+“4»)020
Study of the scope of statisticgineliide’: aa Concept of Economics and Significance of Statistics in Economics
are able to analys
than otherwise.
meaningfully analysed when 4,
‘d with quantitative data,
statistical dats I
problems much better than &
fnemployment in India is more
size of unemployment is SUP}
jsecr MATTER OF STATISTICS
matter of statistics include:
d Inferential Statistics.
‘Subject Matter of Statistics
Descriptive Statistics } Inferential Statistics
Descriptive Statistics #EfETS'tO tho,
. These methods relate to such
| the students of Class XI estimations as ‘measurement of central tendencies’ (average
| to note that the concept mean, median, mode), ‘theasurement of dispersion (mean
+ of universe or population deviation, standard deviation, etc.), ‘measurement of
} fasa spectic meaning correlation’, etc({Example: Descriptive statistics is used when
s nsiatsics OR, you estimate average height of the secondary students in
your school, )Likewise, descriptive statistics is used when you
find that marks in science and mathematics oft students in
. 5 two components: Descriptive
Subject
Statistics an\
') Descriptive Statistics:
} itshould be interesting for + yi
iple: Universe or all classes are intimately related to each othe!
population size is 1,000 i a
Fpuaiy contig (2) Inferential Statistic:
1,000 students for your d
tatistical study.
Inferential Statistics
en(sal
Vee population refers to the
aggregate of all items or units relating to any subject.) for
example, if your class teacher estimates average weight of
the entire class (called universe or population) on the basis
of average weight of only pee of students of the class, he
is using inferential statistic; Concept of Economics and Significance of Statistics in Econo
has emerged to be of crucial
: However, it has certain limitations.
Thus, writes Newshome that, “Statistics must be regarded as an
instrument of research of great value but barring severe limitations which
are not pos ble to overcome.” Following are some notable limitations
of Statistics:
significance in all w
(Example: It may be a statistical fact
that your class teacher earns & 50,000 per month. But, as this
fact relates to an individual, it is not to be deemed as a subject
matter of Statistics. However, it becomes a subject matter of
Statistics if we study income of school teachers across all parts
of the country, for purpose of finding regional differences in
Inco)
Chk loe nadie
. Pe = ii equirement: To compare
data, it is essential that statistics are-uniform in quality.Data
fea te stra pene OST For
example, production of food grains cannot be compared with
the production of cloth. It is because cloth is measured_in
metres and food grains in tonnes. Nevertheless, it is pos
to.compare their value instead of the volume.
le
(4) Res: e only on an Average: Most statistical findings
are true only as averages. They express only the broad
tendencies.
‘or instance, if it is said that per capita
income in India is ¥ 50,000 per annum, it does not mean that
the income of each and every Indian is € 50,00Q per annum.
Some may have more and some may have les:
(5) Without Reference, Results may Prove to be ‘iciles
order to understand the conclusions precisely, i€i8HeCESSaty
. Otherwise,
they may proye to be wrong. OU ae, ete ee ee
Example: In the business of cloth, profits earned during thre,
years may be & 1,000, % 2,000 and & 3,000 respectively, ¢,,
the other hand, in the paper business profits earned during
the same three years may be % 3,000, & 2,000 and @ 1,095,
respectively. Thus, the average profit in both the businesses
comes to % 2,000 per annum. It may lead to the conclusion tha,
both the businesses have similar economic status, but it
not be true. We may actually find that whereas cloth-busin
making progress, paper-business is on.the decline.
‘an be used only by the Experts: Statistics can be used only
by those
persons who have s| ecial knowledge of statistical
methods ies SESE ge PaBEOTE ESB
dls,
c
mnoumakessenslesusenofsasie# 1¢ can, therefore,
be said that data in the hands of an unqualified person is
like a medicine in the hands of a quack who may abuse it,
leading to disastrous consequences. In the words of Yule and
Kendall, “Statistical methods are most dangerous tools in the hands
of an inexpert.”
(D7ione_to Misuse: Misuse of Statistics is very common,
x ven
. Itis usually said, “Statistics are like
ou can make a god or a devil, as you pleas
clay by which ye
se)
4. Importance of Statistics in Economics
Following words of Prof. Tippet very aptly capture the importance
of Statistics in Economics: “A day might come when the department
of Economics in the universities will go out of the control of economic
theoreticians and come under the control of statistical workshops, in the
same manner as the department of physics and chemistry have come under
the control of experimental laboratories.” Indeed, Statistics has emerged
as the lifeline of Economicseltsissbecause-ofsthe»growingausero!
Statitien"t5y THE SCOOT CHEE Th :
bavebeenadded:tothehorizons'of' Economics. Students of Class
XI may note the following points to highlight the significance of ¥
Statistics in Economics.
ey) Quantitative Expression of Economic Problems: Consider
one oe Problem, be it the problem of unemployment
‘oblem of ‘ice. ri . oar
exports, T ater s ee or the problem of shrinking - (3) Working out Cause and Effect Relationship: Economists try
@)
:
Cerner Eecnonics ant Sentence dt Satctes in Eccneries: oe a
For example, if it is the problem of unemployment, we make
its quantitative expression stating that (say) 20 per cent of the
India’s working population is unemployed or that between
the years 1995-2010 the percentage of unemployed working
population has tended to increase from 18 per cent to
QA per cent.
(2) Inter-sectoral and Inter-temporal Comparisons: Economists
do not stop merely at the quantitative expression of the
problems. They would try to further comprehend it through
inter-sectoral and inter-temporal compariso
sorrel shereronsmysd ysing the problem of
u
unemployment, the economists would like to know the
magnitude of unemployment across rural and urban
sectors of the economy. They would like to know what
percentage of rural population is unemployed compared
to the urban population.
ean making a comparison
(say) over different plan periods of the rural and urban
unemployment.
to find out cause and effect relationship between different sets
of data. TI is
ve
. Thus, through their statistical studies, if the
economists come to know that it is because of the decline in
demand that investment in the economy has tended to shrink,
they can suggest the government to adopt such mgasures as
would increase the level of demand in the economy)
Construction of Economic Theories or Economic Models:
he well-known inverse
commodity and its demand.
) is an established
statistical relationship, and therefore, is a part of economic
theory. Is the construction of theoretical relationships or
models possible without statistical experiments? Certainly
not.
s
(i) Statistics faciitates
inter-sectoral and
intertemporal
comparison.
(i) Statistics helps to
establish cause and
efect relationship
between diferent
economic variables
that have facilitated
the construction of
economic theories. is SS
a omics and Si of Statistics nies.
f and Significance of Statistics in Econom
PL of Economics and S
‘Economists do force:
sting throug),
(5) Economic Forecastin, ting we do not me;
Siatistical studies. By the term fore
some astrological prediction
“an
|
of
of
‘al
level
some
s studying
, the economists can make statisti
ely trend or pattern of the pric
helps us in future planning. }
price level over sev
forecasting
in the nea
3; How does the finance minister
se taxation as a source of
10
‘Economic Equilibrium:
re
ere
im. It is
through the use of statistical methods that the economists
have evolved some eco-fundamentals (which you will study
in Class X11) telling us how profits of the producers are
maximised or how consumers get maximum satisfaction.
Thus, uch is the significance of Statistics in Economics that
t.economist of the past century) had to concede
that “Statistics are the straw out of which I, like every oth
have to make bricks.” Surely, Statistics is the
economic studies, and the be;
hub to precisely unders
‘conomist,
hub of the wheel of
ginners of Class XI must focus on the
‘and the movement of the entire wheel,
| 5 sedlistieal methods are No Substitute for Common Seas
Ukewise, average size of shoes for the
ix’, But it would be foolish if the school
oes of the sizesix for all of you, Surely this Concept of Economics and Significance of Sta
SAbistiust of Statistics
Sane people have misgivings about Statistics and make observations like the
following:
(i) Statistics is a rainbow of lies.
{ji) Statistics are tissues of falsehood.
(iii) Statistics can prove anything.
(iv) Statistics cannot prove anything.
(v) aati are like clay of which you can make a god or a devil, as you
please.
(ace
Indeed, one can present statistical information in a manner that tends to
distort the facts and thereby mislead the people. For instance, the government
claimed that in 2011, per capita income in India increased by about 17 per
cent. On the other hand, the opposition party claimed that in 2011, per
capita income increased by 5 per cent only. But the difference lies in the fact |
that whereas government estimates are based on current prices, those of the |
opposition party are based on the 2004.05 prices. It is difficult for a layman
to understand this difference. He will just be confused or perhaps befooled
by the claims and counterclaims of the government and the opposition party. |
cas Distrust? |
Distrust of Statistics arises not because there is anything wrong with Statistics
asa subject matter. f dtoma a
‘Main causes for the distrust of Statistics are as under |
(i) Different kinds of Statistics are obtained in respect of a given problem. |
(ii) Statistics can be altered to match the predetermined conclusions.
(iii) Authentic Statistics can also be presented in such a manner as to confuse
the reader.
(iv) When Statistics are collected in a partial manner, the results are generally
wrong. Consequently, people lose faith in them.
| However, it may be noted that if Statistics are presented wrongly, then the
faut does nat lie with Statistics as a subject matter. THe th
Statistics, as such, ido not prove anything, ‘They ‘are simply tools’in the
if a statistician misuses the data, then the blame
lies squarely on him and not on the subject matter. A competent doctor can
cure.a disease by making good use of the medicine but the same medicine
in the hands of an incompetent doctor becomes a poison. The fault in this
case is not of the medicine but of the unqualified doctor. In the:same way,
‘Statisti¢s is never faulty. but, the faultdies'with the users. t of Economics and Significance of Statistics in Economics
in fact, Statistics should not be relied upon blindly nor distrusted outright.) T° What k
“Statistics should not be used as a blind man uses a lamp post for support z ;
rather than for illumination, whereas its real purpose is to serve as illumination la What
and not as a support.” w® Who is
in making use of Statistics one should be cautious arid vigilant. In the words 1® What i
‘of King, “The science of Statistics is the most useful servant, but only of great Th Short A
' ) Scarci
value to those who understand its proper use."
It is the duty of the students of Economics to make use of know-how of
Statistics to discover the truth rather than to cover the truth. Proble
1 By Explai
Following are some essential remedies of the distrust of Statistics: 4 Briefly
While making use of Statistics, & Distin
be taken care of,! Define
The user should be impartial. He should make use onl
i ly of the
relevant data and draw conclusions without any bias or prejudice. ! t ell,
vi ' @ distin
pple tatistics should be used onl & et
minimise the possibilty of misuse. nt. Byte experts to Vo Wile ee eee ee ee ce
N,, we know that,
in the plural sense,
data or quantitatiy
: ¢ information capable of some_meaningful
conclusions. In other words, in data, we include that information
which is capable of numerical
expression. Let us recall some
examples of data:
Statistics means
QO that there’are ej
20 in Punjab.
O 20 per cent of the people in the
unemployed in India comp;
Q of the tot:
to India.
ght sugar mills in Haryana compared to
working age group are
ared to only 2 per cent in USA.
al cattle population of the world, 50 per cent belongs
The present chapter focuses on the collection of d
ata, including:
1) sources of data and (ii
methods of collecting data. But before
a. For a student '6f
o undéistand) *
1 explainra Soci on roblem,/for example,
em of unemployment or the problem of poverty, While
analysing the problem we also try to understand the causes behind
the problem as also the possible solutions. The entire exercise
needs a comprehensive support of numerical facts, called data.
the prol
1. Primary and Secondary Sources of Data |4
‘There are two sources of data:
(i) Primary Source, and
(it) Secondary Source. <
Primary Source: You want to know about the quality of life of
the people in your town. You may like to ascertain the quality of
life in terms of per capita expenditure of different households in
your town. You decide to collect the basic data yourself through
statistical survey(s), of course with the help of investigators Data
While doing this exercise you are relying ,
“Thus, primary source of dats imp
or field worke
primary source of the dat ee
Pilection of data from its source of origin. It offers you fi,
hand quantitative information relating to your statisti
are contacting the,
formation) and obtaining the desig
on on per capita expenditure of differ,
quantitative
households in your town.
i ata i on.of data. ft Ince Of origi
Secondary Source: Secondary Source of collection of data imply
obtaining the relevant statistical information from an agency, ¢,
an institution which is already in possession of that information
‘fo continue with the previous example, data relating to ty
quality of life of the people of your town (or the data on pe;
capita expenditure) may have already been collected by the
State Government. You can simply approach the concerned
Government departmentand request for the desired information
This will be a Secondary Source of data for you. Thus, secondary
source implies that the desired statistical information alread,
exists and you are simply to collect it from the concerned ageng+
or the department. You are not to conduct statistical survey(s)
ys f and you are not to contact the respondents (people
offering basic information). Of course, you are not getting firs
hand information relating to your statistical study. You are simply
relying on the information which is already existing.
fers'youy Primary data’ and,
Let us clarify the!
difference,
‘
ney Data: Data collected by the investigator for his owt
Rurpose, ou the first time, from beginning to end, are called
primary data. These are collected from the source of 0! ony
‘on who collects these (7
‘The concerned investigator is the first pe
informati
the socio-ce
be
te, you ma interested
lying, | Ifwe are collecting
as
somebody else, itis
secondary data.
omic state of those students in your Glass XT who | data fom ts source
secured first division in their matriculation examination. You 1 otorgi.it Beit
collect information regarding their pocket allowance, their family | | U™® ‘ae
income, educational status, their family members and the like. |" Mweaeusngee®
All this information would be termed as primary information or | Wonunipaeddy 722 7)
primary data, since you happen to be the first person to collect | '
this information from the source of its origin.
Secondary Data: In the words of M.M. Blair, “Secondary data are
those which are already in existence, and which have been collected, for some
other purpose than the answering of the question in hand.” {N@CBRAINE
ways which are
published by the Railway Board, would be secondary
data for any researcher.
.Ppticipal Differences between Primary and Secondary Data
The following are some principal differences between primary
and secondary data: era
Difference in Originality:(Primary data are original because
these i: collected by the investigator from the source of their
origin Against this, secondary data are already in existence
and, therefore, are not original.
Difference in the Suitability of Objectives: Primary data are
Dp) always related to a specific objective of the investigator ‘these
data, therefore, do not need any adjustment for the
concerned aedXOn the other hand, secondary data have
already been collected for some other purpose.Therefore,
these data need to be adjusted to suit the objective of study
pa hand.)
(3) Difference in Cost of Collection:
‘ econdary data
ly collected from the published or unpt
le lished
Accordingly, these are much less gxpensive,) ;
2 Statice AM Eaiinimtan Data
Data are data, wl icthy,
hese are Classified as primary or second,”
just on the basis of their collection: first-ha ne or ceo and. Tg
‘a particular set of data when collected by ie gator for,
specific purpose from the source of origin, yor 2 ean ao day,
‘And the same set of data, when used by some o| nr ie gator lr
his own purpose, would be known as secondary lata, Thus, Seerg
has rightly pointed out, “The distinction between primary and secondary
data is one of the degree.
primary or seconds
& How Basic Data is Collected: :
Some Statistical Methods/Modes of Data Collection
e collected from its primary source, how
the study of a set of statistical methods or
() MailingMétliod, and (ji) Eaunietator’s Method
Direct PERSONAL INVESTIGATION
in other words, the investigator establishes direct relation with
the persons from whom the information is to be obtained. The
success of this method, however, requires that the investigator
should be very diligent, efficient, impartial‘and tolerant.
Direct contact with the workers of an industry to obt
ain
information about their economic conditions is an example of
this method. ‘
Shitability
This method of collecting
when:
‘
primary data is suitable particularly
(1) the field of investigation is limited or not very
(2) a greater degree of or
urge.
lity of the data is required. Cokatont 0s aE
(8) information is to be kept secret:
(A) accuracy of data is of great significance, and
(8) when direct contact with the informants is required.
Merits
Data thus collected have the following merits:
(1) Originality: Data have a high degree of originality.
(2) Accurac;
Data are fairly accurate when personally collected.
(8) Reliability: Because the information is collected by the
investigator himself, reliability of the data is not doubted.
(4) Related Information: When in direct contact with the informants,
the investigator may obtain other related information as well.
(6) Uniformity: There is a fair degree of uniformity in the data
collected by the investigator himself from the informants. It
facilitates comparison.
(6) Elastic: This method is fairly elastic because the investigator
can always make necessary adjustments in his set of questions.
merits
However, the method of direct personal investigation suffers
from certain demerits, as under:
Difficult to Cover Wide Areas:(Direct personal investigation
becomes very difficult when the area of the study is very wide. )
Q nal Biast This method is highly prone to personal bias of
the investigator. Asa ir-eredibiti
5 toe
‘Costly: This method is very expensive in terms of the time, :
money and efforts involved. )
“ht Limited Coverage: In this method, area of investigation is
generally small. The resultsare, therefore, less representative.
This may lead to wrong conclusions.
You are to conduct direct personal investigation on the quality of teaching ?
in a school. Who are your informants? What difficulties do you expect to
encounter in such an exercise?
Inpinecr ORAL INVESTIGATION
Indirect oral investigation is the method by which information is obtained
not from the persons regarding whom the information is needed. Cotection of Data
apse TEMES AE A et, ky
imple, by this me the dat he economic conditi,
ex
) be collected from their employers rather 24
the workers may be collected from t loyers rather!
the workers themselves.
sit bility
This method is suitable particularly when:
(1) the field of investigation is relatively large.
(2) it is not possible to have direct contact with the Concerns
informants.
(8) the concerned informants are not capable of
information because of their ignorance or illiteracy,
Siving
(4) investigation is so complex in nature that only experts g,
give information.
Merits
Some of the notable merits of this method are as under:
(1) Wide Coverage: This method can be applied even when the
field of investigation is very wide.
(2) Less Expensive: This is relatively a less expensive method
compared to Direct Personal Investigation,
(3) Expert Opinion: Using this method an investigator can eel
opinion of the experts and thereby can make his information
more reliable.
(4) Free from Bias: This method is relatively free from the
personal bias of the investigator.
(8) Simple: This is relatively a simple approach of data collecion
lemerits
However, there are some demerits, as under:
(1) Less Accurate: The data collected by this method
relatively less accurate. This is because the information *
obtained from persons other than the concerned informa
(2) Biased. eo
edtving informations”
8) Doubtful Conclusion:
conclusions due to carel
a il!
This method may lead to doub!
essness of the witnes
eS. (DIFFERENCE BETWEEN Direct PERSONAL INVESTIGATION.
‘AND INDIRECT ORAL INVESTIGATION
AND INDIRECT ORAL INVESTIGATION.
The difference between direct personal investigation and indirect
oral investigation is as under:
(1) In the case of direct personal investigation, the investigator
establishes direct cl ‘the? ants\’On the other
hand, in the case of indirect oral investigation, information
is obtained by contactingvother®than those about whom
information is sought.
(2) Direct Personal Investigation i is generally possible when the
ldvofii avis '$miall. On the other hand, indirect
oral investigation is generally preferred when theffiéld¥of
investigatiomisrrelatively laige. ”
(3) In the Direct Personal Investigation, the investigator must
be well versed in the language and cultural habits of the
informants. There is no such requirement in the case of
Indirect Oral Investigation:
4 rE inyesti
i x g than the indirect
investigation.
UTearning by doing
You are keen on finding statistical information on available Health Car
facilities in your locality comprising 200 families. How would you'approach ?
the issue, and which method of investigation would you prefer to adopt
This method is suitable particularly when:
(a)
(2) the area of investigation is large.
(hg nora is 1 be sed by jones; magarines rao,
(4) avery high degree of accu racy of information is not required.
Collect Collection of Data
préeits
Principal my
(1) Economical: This method is quite economi
time, money or efforts involved.
(2) Wide Coverage: This method allows a fairly wide coverage gs
investigation.
(3) Continuity: The correspondents keep on supplying almog
regular information.
4) Suitable for Special Purpose: This method is particula
P : beatae: arly
suitable for some special-purpose investigations, eg., price
quotations from thedifferent grain markets for the construction
of Index Number of agricultural prices.
Démerits
Following are some notable demerits of this method:
(1) Loss of Originality: Originality of data is sacrificed owing to
the lack of personal contact with the respondents.
(2) Lack of Uniformity: There is lack of uniformity of data. This
is because data is collected by a number of correspondents.
(3) Personal Bias: This method suffers from the personal bias of
the correspondents.
(4) Less Accurate: The data collected by this method are not
very accurate.
(ARatansimaGeltestion:"Generaly, there is a delay in the
collection of information through this method.
DforMaTION THROUGH QUESTION) (AIRES Al SCHEDULES
Under this method, the
Keepinigiinwiewsh@objectiverof theenquiry. There are (eo;ways
collecting | ion on the basis of qu :
(Y) Maine Metnop
Under this method, questionnaires are’ mailed tetthe informants
a ees Maltached with the questionnaire giving the purpose 0!
nay is also assured that the information would be kep!
Ee : he informant notes the an: against the questions
and returns the completed questionnaire to the investigator.
as under:
its of this method a
in terms gf goaanitity
‘This method is most suited when:
(2) the area of the study is very wide, and
(2) the informants are educated.
Plerits
rhe following are the main merits of this method:
(1) Economical: This method is economical in terms of time,
money and efforts involved.
(2) Original: This method is original and, therefore, fairly
reliable. This is because the information is duly supplied by
the concerned persons themselves.
(3) Wide Coverage: This method allows wide coverage of the
area of study.