Concept of Sample, sampling, Characteristics of a good sample, Probability Sampling, Non Probability Sampling, Types of Data, Primary Data, Observations, Interview, The questionnaire method, Open v/s Closed questions, Precaution in Construction of Questionnaire, Collection of Secondary Data,
2. Concept of Sample
ο΄ Population : Population refers to the entire group
of people, events, or things that the researcher
wishes to investigate.
ο΄ Unit or element : is a single member of a
population.
ο΄ Sample: A sample is a subset of the population.
It comprises some members selected from
population.
3. What is sampling?
ο΄ Sampling is the process of selecting a sufficient
number of elements from the population, so that
the results received after the study of sample
can be generalized for the entire population.
4. Sampling Decisions or
Characteristics of a good
sample
ο΄ Sample should be of optimum size
ο΄ It should represent the entire population
ο΄ It should result in a small sampling error
ο΄ It should be within budget available for the
research study.
ο΄ Time
5. SAMPLING METHODS
Probability Sampling Non Probability Sampling
Convenience
sampling
Judgment
Sampling
Simple Random
Sampling
Systematic
Sampling
Stratified
Sampling
Multi stage Cluster
Sampling
Quota
sampling
6. Probability Sampling
ο΄ Simple random sample
ο΄ Selection by equal probability
ο΄ Systematic sample
ο΄ Selection from sample frame at a constant interval
ο΄ Stratified sample
ο΄ Proportional representation of population characteristics
ο΄ Multi-stage cluster sample
ο΄ Selection from groupings of population units
7. Non Probability Sampling
ο΄ Convenience sampling
ο΄ By accessibility
ο΄ Judgement sampling
ο΄ By choice of researcher
ο΄ Quota sampling
ο΄ By proportion, but not at random
8. Types of Data
ο΄ Primary Data : The primary data are those which
are collected afresh and for the first time, and
thus happen to be original in character.
ο΄ Secondary Data : The secondary data are those
which have already been collected by
someone else and which have already been
passed through statistical process.
9. Methods of collection of
Primary Data
ο΄ Observation
ο΄ Interview
ο΄ Questionnaire
ο΄ Survey
10. Observations
ο΄ Observation involves viewing and recording
individuals, groups, organizations or events in a
scientific manner in order to collect valuable
data related to the topic under study.
ο΄ It also includes data collection with the help of
some machinery.
14. The questionnaire method
οThis is the simplest and most often used method of primary data
collection
οThere is a pre-determined set of questions in a sequential format
οIs designed to suit the respondentβs understanding and
language command
οCan be conducted to collect useful data from a large
population in a minimum cost
15. Criteria for questionnaire design
ο΄ The spelt out research objectives need to be
converted into specific questions
ο΄ It must be designed to engage the respondent
and encourage meaningful response
ο΄ The questions should be designed in simple
language and be self-explanatory
16. Process of constructing the
Questionnaire
ο΄ Convert the Research Objectives
into the Information Needed
ο΄ Content of the Questions
ο΄ Selection of type of question
ο΄ Open v/s Closed
ο΄ Closed β Dichotomous, Multiple Response, Scale
ο΄ Order of questions
ο΄ Pilot Testing
17. Open v/s Closed questions
Open Question
ο΄ What is your opinion about the performance of
your CEO?
Closed Question
ο΄ What do you think of the CEO's performance in
his job
(Please tick the appropriate response)
Very good Good Fair Poor Very poor
5 4 3 2 1
18. Precaution in Construction
of Questionnaire
ο΄ Questions should flow logically from one to the
next
ο΄ General questions should be asked before more
specific ones
ο΄ Demographic questions should come at the end
or beginning.
ο΄ long-worded questions should be avoided
19. Precaution in Construction
of Questionnaire
ο΄ Double-barreled questions should be
avoided. Questions that refer to two or
more issues within the same question.
Where respondent may agree with only
1 part of multipart statement.
ο§ Do you think Nike offers better pricing
and variety than other brands
ο΄ Distinguish between instructions, questions and responses
20. Collection of Secondary
Data
ο΄ Publications by government
ο΄ Publications by other institutions
ο΄ Reports prepared by scholars, universities,
economists etc.
ο΄ Other sources (autobiographies, books,
newspapers etc.)
21. Recommend an appropriate
data collection method in
following situations:
ο΄ To understand the buying behavior of shoppers
in a mall
ο΄ To get information from the persons affected
from flood
ο΄ When data is required from large geographical
area
ο΄ When sample units are illtreat
ο΄ When the topic is highly technical