.

1. Collection of data
Data – Information which can be expressed in numbers
Two sources of data – 1) Primary data
2) Secondary data
Primary Data
Primary data is original data collected by the
investigator

2. Methods / Sources of Collection of
Primary Data :
a] Direct Personal Interview :– Data is personally
collected by the interviewer.
b] Indirect Oral Investigation :– Data is collected
from third parties who have information about subject
of enquiry.
c] Information from correspondents :– Data is
collected from agents appointed in the area of
investigation.

3. Cont….
 d] Mailed questionnaire :– Data is collected through
questionnaire [list of questions] mailed to the
informant.
e] Questionnaire filled by enumerators :– Data is
collected by trained enumerators who fill
questionnaires.
f ] Telephonic interviews :– Data is collected
through an interview over the telephone with the
interviewer. Questionnaire – A list of questions with
space for answers.

4. Advantage
 Primary data is specific to the needs of the researcher at the
moment of data collection. The researcher is able to
control the kind of data that is being collected.
 It is accurate compared to secondary data.
 The researcher exhibit ownership of the data collected
through primary research. He or she may choose to make it
available publicly, patent it, or even sell it.
 Primary data is usually up to date because it collects data in
real-time and does not collect data from old sources.
 The researcher has full control over the data collected
through primary research. He can decide which design,
method, and data analysis techniques to be used

5. Disadvantage
 Primary data is very expensive compared to secondary
data.
 it might be difficult to collect primary data.
 It is time-consuming.
 It may not be feasible to collect primary data in some
cases due to its complexity and required commitment.

6. Secondary data
It refers to data that that was collected by someone other
than the user.
Example Census
Source / method of collecting Secondary data
1) News Paper
2) Books
3) Journal
4) Govt. records
5) Website
6) Dairy

7. Advantage
 Secondary data is easily accessible compared to
primary data.
 Secondary data is available on different platforms that
can be accessed by the researcher.
 Secondary data is very affordable. It requires little to
no cost to acquire them because they are sometimes
given out for free.
 The time spent on collecting secondary data is usually
very little compared to that of primary data.

8. Disadvantage
 Secondary data may not be authentic and reliable. A
researcher may need to further verify the data
collected from the available sources.
 Researchers may have to deal with irrelevant data
before finally finding the required data.
 Some of the data is exaggerated due to the personal
bias of the data source.
 Secondary data sources are sometimes outdated
with no new data to replace the old ones.