This document discusses various techniques for collecting data. There are two main types of data collection: primary data and secondary data. Primary data involves directly collecting original data through methods like personal investigation, questionnaires, experiments, census, and sampling. Secondary data involves obtaining existing data from published sources like statistical agencies or unpublished sources like government records and research studies. Some specific primary data collection methods discussed include direct and indirect personal investigation, using correspondents, questionnaires sent by post or enumerators, experiments, census, and sampling.

1. DATA COLLECTION TECHNIQUES
M.Rajkumar.M.sc,M.Phil

2. COLLECTION OF DATA
The process of getting values and acts
from an observation or experiments
is called collection of data

3. collection of data
Two types
1.primary data
2. secondary data
1. primary data
• Direct personal investigation
• Indirect oral investigation
• Information through corresponds
• The questionnaire method
• Experiments
• Census
• Sampling method

4. 2 . Secondary data
published sources
unpublished sources

5. 1 . primary data
Data originally collected for
investigation are known as primary
data.

6. Direct personal investigation
The investigator has to
contact the sources of
information directly and
personally.

7. INDIRECT ORAL INVESTIGATION
There are certain situations when the in
formations cannot be approached directly
. in such situations, we have to collect
data from those persons who may possess
some knowledge about the investigation .
Such persons are known as ‘witnesses ‘.

8. INFORMATION THROUGH
CORRESPONDENTS
Inthismethod, theinvestigatordoesnot collectthe
information directlyfromtherespondents.The
taskishandedoverto a fewpersonsor a groupof
persons, who areknownas ‘correspondents’.

9. THE QUESTIONNAIRE METHOD
In this method, the information is obtained from the
informants through questionnaire.
This method is of two forms;
• questionnaire sent through post
• questionnaire sent through enumerators

10. 1. questionnaire sent through post
In this method the questionnaire is mailed to the
informants. It also carries a request for the quick
response and lays down the aims and objectives of
collecting the information . In this method, the
return postage expenses are generally borne by
the investigator.

11. 2 . Questionnaire sent through enumerators
The enumerators go to the informants with a
prepared questionnaire and get the replies to the
questions. This method is generally used by public
organizations like FICCI, NCAER, etc., for the
research projects that need a high rate of
response.

13. EXPERIMENTS
Data can be collected by doing
experiments.
The amount of oxygen present in water
samples can be collected by titration
experiments.

14. EXPERIMENTS
WATER SAMPLES AMOUNT OF OXYGEN IN ml/l
POND WATER 5 .1
RIVER WATER 4 .8
WELL WATER 3 .7
SEA WATER 4 .3

15. CENSUS
Census is a method of collection of data.
Census is the counting of all the members of
a population one by one.
e.g., Human population is assessed by
census.
The trees in a coconut grove are counted by
census method.

16. sampling
sampling is a method of collection of data
techniques.
sampling is the process of getting a
representative fraction of a population.
In sampling method, a small group is taken
from a large population. This small group is
the sample. Analysis of the sample gives an
idea of the population.

18. 2 . Secondary data
Data which are obtained from
published or unpublished sources
are known as secondary data.

19. PUBLISHED SOURCES
There are certain international,
national and local agencies which
publish statistical data on a regular
basis.

20. UNPUBLISHED SOURCES
There are various sources of unpublished data
such as the records maintained by the various
government and private offices , studies made by
the research scholars in the universities and other
research institutions, etc.,

21. Thank you