MMW REVIEWER Qualitative Variables (Categorical)- They are variables

that are classified to some attributes or categories.

LESSON 1: BASIC CONCEPT OF Quantitative Variables (Numerical-valued)- They are
STATISTICS classified according to numerical characteristics.
Numerical-valued variables can be treated qualitative
STATISTICS- is a branch of applied mathematics
variable when they are grouped into class intervals
that deals with the collection, organization,
presentation, analyzation, and interpretation of  Discrete Variables are variables whose values
data. are obtained by counting
 Continuous Variables are variables whose
DESCRIPTIVE STATISTICS- deals with the collection values are measuring
and presentation of data and summarizing the
Variables with regards to the functional relation
values that describe the group’s characteristics.
The most common summarizing the values are the  Independent Variable- variable manipulated by
measures of central tendency and the measures of an experimenter to determine its effect on the
variation dependent variable
 Dependent Variable- variable whose value is to
EXAMPLE: If only 12 out 60 students obtained scores be predicted; it is also referred as the criterion
above 45, then it means that the exam is too difficult, or variable or predict and variable
the teaching strategy was not effective so either the
teacher has to give a less difficult exam or reteach the Scales of Measurement
topic.
 Nominal Scale- Data in the nominal level are
INFERENTIAL STATISTICS- deals with the predictions only qualitative classification. (Gender, religion
and inferences based on the analysis and interpretation affiliation, political affiliation, civil status, race)
of the results of the information gathered by the  Ordinal Scale- Data in the ordinal Scale include
researchers or statistician. Deals with making a variables which can be ranked or ordered in
judgment or a conclusion about a population based on terms of which has less which has more quality
the study of a sample that is taken from the population represented by the variable but cannot be
(t-test, z-test, analysis of variance, chi-square, and quantified or compared. (Product satisfaction,
Pearson r.) professional rank, academic awards, pain level,
military rank.)
EXAMPLE: The manager of department store records  Interval Scale- Data in the interval Scale take all
the number of buying customers daily for seven the properties of ordinal variables and can be
consecutive weeks and then estimates the average quantified and compared. Interval variables
number of buying customers for the following weeks. have arbitrary zero values. (No Zero)
(Temperature, Standardized Exam, Calendar
POPULATION- It consists of all the subjects (people,
Time)
objects, events) that are being studied. SAMPLE- It is an
 Ratio Scale- Data in the ratio scale take all the
unbiased estimate of the population
properties of interval level with identifiable zero
PARAMETER- is a numerical measure that describes a point. (Height, weight, age, salary, area,
characteristics of a population. STATISTIC- is a volume.)
numerical measures that describes a characteristics of a • TRUE ZERO POINT- is the point corresponding
sample. VARIABLE- is a numerical characteristics or to the absence of the thing being measured
attribute associated with the population being studied.
  Disadvantage: Problem arises only when the
agencies doesn't have management information
LESSON 2: METHODS OF system
COLLECTING THE DATA
Observation Method- It is a scientific method of
PRIMARY DATA- data coming from the primary sources investigation that makes possible use of all senses to
which include government agencies, business measure or obtain outcomes/responses from the object
establishment, organizations, and individuals who carry being studied.
original data or have first hand information relevant to a
given problem.  Advantage: observation method is usually
applied to respondents that cannot be asked or
SECONDARY DATA- data coming secondary sources need to not speak, especially when behavior of
which includes newspapers, magazines, journals, and persons/culture of organization/ performance
published materials. outcomes of employees/ students are to be
considered.
Methods of Collecting Data
 Disadvantage: Subjectivity of the information
Direct or Interview Method- It is a person-to-person sought cannot be avoided.
interaction between an interviewer and an interviewee.
Experimentation Method- It is used when the objective
Tape recorded or written views will help the researcher
is to determine the causeand-effect of a certain
obtain exact information from the interview.
phenomenon under some controlled conditions.
 Advantage: Precise and consistent answers can
 Advantage: There is objectivity of information
be obtained by modifying or rephasing the
since a scientific method of inquiry is used.
questions especially to illiterate respondents or
 Disadvantage: it is too difficult to find
to children under study.
respondents with almost similar characteristics.
 Disadvantage: It is time, money, and effort
consuming and it will be applicable only for
Taro Yamane’s Formula n= 𝑵 𝟏+𝑵𝒆 𝟐
Determining the Sample Size:
small population, except when conducting a
census.
Where:
Indirect or Questionnaire Method- It is an alternative
method for the interview method. Written responses n=required sample size
are obtained by distributing questionnaires to the N=the size of the finite population
respondents through email or hand-carry e=margin of error (1%, 3%, 5%, 10%)
Note: Margin of error is the error we expect to commit
 Advantage: Lesser time, money, and efforts are in getting the sample. It is an estimate parameter
consumed.
 Disadvantage: Many respondents may not be LESSON 3: SAMPLING TECHNIQUES
consistent due to the poor construction of the
SAMPLING- It is the process of obtaining samples from
questionnaire. The meaning of the questions
the population
are different from each respondents.
RANDOM/PROBABILITY SAMPLING- It is a method by
Inconsistent responses can no longer be
which every element of a population has an equal
modified
chance of being included in a sample
Documents or Registration Method- enforced by the
RANDOM SAMPLING
private organization and government agencies for
recording purposes 1. Simple Random Sampling- It is a method in
which every individual or item from a frame has
 Advantage: Organized Data
 the same chance of selection as every individual
or item. Most elementary random sampling
techniques.

2. Systematic Sampling- the N individuals or items

in the framed are partitioned into groups by
dividing the size of the frame N by the desired

 That is, k= 𝑵/𝒏

sample size n.

N=the population size

n=the sample size

3. Stratified Sampling- the N individuals or items

in the frame are first subdivided into separate
subpopulations, or strata, according to some
common characteristic. Simple random sample
is conducted within each of the strata, and the
results from the separate simple random
samples are then combined.

4. Cluster Sampling- the N individuals or items in

the frame are divided into several clusters so
that each cluster is representative of the entire
population. Random sampling of cluster is then
taken, and all individuals or items in each
selected cluster are studied. It is used when the
population is large or when it involves subjects
residing in a large geographic area.

Non-Random Sampling

1. Purposive (judgment) Sampling- The

respondents of the study will be chosen based
on their knowledge of the information required
by the researcher. It is more sophisticated type
of sampling which emerges when personal
judgment, presumably based on prior
knowledge.
2. Quota Sampling- This technique is commonly
used in opinion poll.
3. Convenience Sampling- technique involves
taking a sample with some priority given to the
convenience with which the sample is taken.
•This technique is resorted to by researchers
who need the information the fastest way
possible.