As pointed out earlier, primary data are the data which are collected from some primary sources i.e., a source of origin where the data generate. These data are collected for the first time by an investigator or an agency for any statistical investigation and analysis.
On the other hand, secondary data are the data which are collected from some secondary sources i.e. the source of reservation or storage where the data are stored after being collected after being collected and used for some purpose by some agency. These data are available either in the published or unpublished from and are collected for the time other than the first time by and investigator or agency for any subsequent investigation.
Distinction Between Primary and Secondary Data
The distinction between the primary and secondary data will be very clear from the following points:
1. On The Point of Source
A primary data is collected from a primary source i.e. the source that generates the data. But a secondary data is collected from a secondary source i.e., the source that upkeeps or hoards the data.
2. On The Point of Time
A primary data is collected for the first time by an investigator or agency who makes use of the data for the first time. But a secondary data is collected for the second or any subsequent time by an investigator who makes use of the data for any subsequent time.
3. On The Point of Shape
A primary data is in the shape of raw material but a secondary data is in the shape of either a work-in-progress or finished goods capable of further processing.
4. On The Point of Conversion
A primary data, after a use is converted into a secondary data but a secondary data can never be converted into a primary data.
5. On The Point of Use
A Primary data goes through further analysis and changes its shape thereby in course of its use. But a secondary data is used as such without any change in its shope. For example, statistics of agricultural production are used as primary data for the purpose of calculating national income while the same are used as secondary data for the agriculture department of a government.
6. On The Point of Resources
A primary data needs more resources in terms of money, machinery and time for its collection and analysis, But a secondary data needs less amount of resources in terms of money, machinery and time for its collection and analysis.
7. On The Point of Precaution
A primary data needs more precaution at the time collection but less at the time of its use. On the other hand, a secondary data needs less amount of resources in terms of money, machinery and time for its collection and analysis.
8. On The Point of Method of Collection
A primary data can be collected by different methods viz. (i) direct personal investigation, (ii) indirect oral investigation (iii) through local reports, and (iv) through schedules and questionnaires. But a secondary data is collected by copying down from some published papers and retained records.
9. On The Point of Method of Collection
A primary data used for a particular purpose whereas a secondary data can be used for different purposes by the different investigators.