Primary data is collected originally by an individual or agency and involves direct collection methods like personal investigation, questionnaires, enumerators, or local sources. Secondary data was originally primary data but became secondary after statistical treatment. Secondary data is collected from official statistics published by government, semi-official sources like the state bank, and other sources like magazines, newspapers, and journals.

1. Primary
and
Secondary DataNADEEM UDDIN
ASSOCIATE PROFESSOR
OF STATISTICS
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2. PRIMARY DATA:
It is collected originally by some individual or agency and original
in character. OR The data is called primary if no statistical
treatment is applied on the data.
Collection of Primary Data:
(1) Direct Personal Investigation:
In this method, enumerator record the information supplied by
the informants personally.
(2) Indirect Personal Investigation:
In this method some agency other than the respondent is selected
to supply the data.

3. (3) Questionnaire Method:
Questionnaire is a list of questions relating to the field of
inquiry. This list of questions is sent by mail to the respondents
with a request that they send it back after duly filling the
entries. A questionnaire should have the following
characteristics:
(i) Its language should be simple.
(ii)Number of questions should not be very large.
(iii)Questions should be in a systematic order.
(4) Collection through Enumerators:
This method is used to overcome the difficulties of the illiterate
people in filling the questionnaire.
(5) Collection through local sources:
These are the reports of the local representatives sent to the
investigator.

4. SECONDARY DATA:
If the primary data have been treated statistically it is no more
primary. It becomes secondary.
Collection of Secondary Data:
(1) Official Statistics:
All the government departments maintain their data and
published it annually.
(2) Semi Official:
The data available with state bank of Pakistan, railway and PIA
are called semi official.
(3) Magazines and Newspapers.
(4) Journals of the universities.