NCERT plus one Economics

1. COLLECTION OF DATA

2. POPULATION or UNIVERSE
A Population or Universe refers to any
collection of specific group of human being
or non-human objects such as educational
institution, geographical area, supply and
demand of a commodity, etc.
SAMPLE
Sample is the representative portion of the
population or Universe.
COLLECTION OF DATA :It is the process of
collecting data or information from different
sources

3. INVESTIGATOR
The Investigator is a person, institution, or
Government that is responsible for conducting the
statistical enquiry and data collection.
ENUMERATOR
Enumerator is the person who actually collects the
data of enquiry.
RESPONDENT
The person or an institution that provide information
to the investigator or enumerator is called
Respondent or Informant.

4. SOURCES OF DATA COLLECTION
SOURCES OF DATA
PRIMARY DATA SECONDRY DATA
PUBLISHED UNPUBLISHED

5. PRIMARY DATA SOURCE
Primary data are those data, which are
collected for the first time by an
investigator
SECONDRY DATA
If the data have been collected and
processed by some other agency or data
that are already collected by the others

6. DISTINGUISH BETWEEN PRIMARY AND SECONDARY
DATA
PRIMARY DATA SECONDRY DATA
It is first hand in use. It is second hand in use.
It is in the form of raw materials. It is in the form of finished products
More reliable and accurate Not reliable and inaccurate
Expensive and time consuming Its not expensive and time saving

7. SOURCES OF SECONDRY DATA
Secondary data can be obtained from published
sources such as government reports,
documents, newspapers, website etc or from
unpublished sources like research works,
records that maintained by private and business
enterprises

8. Important instruments for data collection
QUESTIONNAIRE/ INTERVIEW SCHEDULE
Questionnaire or interview schedule is a set of
questions prepared by investigator on phenomenon
he going to study. The major difference between
questionnaire and interview schedule is If an
investigator or enumerator himself fills the forms
by asking questions to the respondents directly, the
form is called Schedule.
If an investigator or enumerator sent the forms to
the respondents to get it filled, the form is called
Questionnaire

9. THE MAIN QUALITIES OF A GOOD QUESTIONNAIRE
ARE THE FOLLOWING.
1. Questionnaire should not be too long.
2. A series of questions should move from general to specific.
3. The questions should not use double negatives.
4. The questions should not be a leading question, which gives a
clue about how to answer.
5. The questions should be precise and clear.
6. The questionnaire should include both open ended and closed
ended questions
7. The questions should not be ambiguous. They should enable
the respondents to answer quickly,correctly and clearly

10. PILOT SURVEY
Once the questionnaire is ready, it is advisable to
conduct a try-out with a small group which is
known as Pilot Survey or Pre-testing of the
questionnaire.

11. Mode of Data Collection/ Methods or techniques
of Primary data collection
There are three basic ways of collecting primary
data:
1. Personal Interviews,
2. Mailing questionnaire
3. Telephone Interviews

12. PERSONAL INTERVIEWS
This method is used when the researcher has access to
all the members. The researcher (or investigator)
conducts face to-face interviews with the respondents
Advantages of Personal Interview
Highest Response Rate
Allows use of all types of questions
Better for using open-ended questions
 Allows clarification of ambiguous questions.
Disadvantages of Personal Interview
 Most expensive
 Possibility of influencing respondents
More time-taking.

13. MAILING QUESTIONNAIRE
When the data in a survey are collected by mail, the
questionnaire is sent to each individual by mail with a request
to complete and return it by a given date.
Advantages of Mailed Interview
 Least expensive
Only method to reach remote areas
 No influence on respondents
 Maintains anonymity of respondents
Best for sensitive questions
Disadvantages of Mailed Interview
 Cannot be used by illiterates
 Long response time
 Does not allow to give explanation of questions
 Reactions cannot be watched.

14. TELEPHONE INTERVIEWS
In a telephone interview, the investigator asks
questions over the telephone
Advantages of Telephonic Interviews
Relatively low cost
Relatively less influence on respondents
Relatively high response rate
Disadvantages of Telephonic Interviews
Limited use
 Reactions cannot be watched
Possibility of influencing respondents

15. CENSUS OR COMPLETE ENUMERATION:
A survey which includes every element of population is
called census or complete enumeration.
Example :In India census are conducted by Registrar
General Of India(R.G.I.). ln India census ,which carried
out every ten years
CENSUS AND SAMPLE SURVEYS
ADVANTAGES
Additional information is to be obtained
More reliable information
Covers the entire population

16. DISADVANTAGES
More time taking
More expensive
More enumerators needed
SAMPLE SURVEY:
Data or information is collected from samples only,
such method of data collection is called sample
survey. A sample refers to a group or section of
population from which information is to be obtained

17. ADVANTAGES
It provides reasonably reliable and accurate information.
 It needed lower cost and shorter time
 More detailed information can be collected
 Smaller team of enumerators is needed
DISADVANTAGES
 Sampling methods can be used only by an Expert
 chances of sampling and non sampling error are high

18. METHODS OF SAMPLING.
RANDOM SAMPLING NON RANDOM SAMPLING
METHODS OF SAMPLING
SIMPLE RESTRICTED
JUDGEMENT CONVINENCE QUOTA
STRATIFIED CLUSTER SYSTAMETIC

19. RANDOM SAMPLING:
In the random sampling every individual has an equal
chance of being selected as a sample . The individuals
who are selected are just like the ones who are not
selected .In random sampling ,samples are selected with
the help of random number tables or Lott’s so this method
is also called lottery method
METHODS OF RANDOM SAMPLING.
Random number tables
Lottery method

20. Random tables contain series of random digits arranged in
rows and columns. These tables are used for getting random
numbers corresponding to which We select items from
population
Examples
 Tippets random table
Fishers and Yates random table
CR Rao’s table

21. LOTTERY METHOD
Under this method all items are numbered or named
on a separate sheet of paper Of identical size and
shape. The slips are folded and mixed in a container.
A blind fold Selection is made of the number slips
required to constitute the desired size of sample

22. NON RANDOM SAMPLING
In non random sampling all the unit of the
population do not have an equal chance of being
selected as sample. The convenience or judgment of the
investigator plays an important role in the selection of
the sample

23. SAMPLING AND NON-SAMPLING
ERRORS
The difference between the actual value of a parameter
of the population and its estimate (from the sample) is
the sampling error.
It is possible to reduce the magnitude of sampling error
by taking a larger sample

24. Consider a case of incomes of 5 farmers of Manipur.
The variable x (income of farmers) has measure-
ments 500, 550, 600, 650, 700. We note that the
population average of
(500+550+600+650+700)÷ 5
= 3000 ÷ 5 = 600.
Now, suppose we select a sample of two individuals
where x has measurements of 500 and 600.
The sample average is (500 + 600) ÷ 2
= 1100 ÷ 2 = 550.
Here, the sampling error of the estimate
= 600 (true value) – 550 (estimate) = 50.

25. NON SAMPLING ERRORS
Non sampling errors are more serious than sampling
errors because sampling error can be minimized by
taking larger sample. It is difficult to minimize non
sampling errors, even taking a large sample. some of
the non sampling errors are:
• Errors in data acquisition: This type of error arises from
recording of incorrect responses.
• Non response errors: It occurs if an interviewer is unable to
contact a person listed in the sample or a person from the
sample refuses to respond .
• Sampling bias: Sampling bias occurs when the investigator
performs biased in the selection of samples or some members of
the target population could not possibly be included in the
sample..

26. LIST OF SOME DATA COLLECTING AGENCIES IN INDIA
Central statistical organization. (CSO)
National sample survey organisation.(NSSO)
Registrar general of India(RGI)
Directorate general of commercial intelligence
and statistics(DGCIS)
Labour bureau

27. The Census of India provides the most complete and
continuous demographic record of population. The Census is
being regularly conducted every ten years since 1881. The
first Census after Independence was conducted in 1951. The
Census officials collect information on various aspects of
population such as the size, density, sex ratio, literacy,
migration, rural-urban distribution, etc. Census data is
interpreted and analyzed to understand many economic and
social issues in India.
The NSSO was established by the Government of India to
conduct nationwide surveys on socio-economic issues. The data
collected by NSS are released through reports and its quarterly
journal Sarvekshana.