What are the merits and demerits of Primary and Secondary sources of Data?

Primary Data

Primary data is the data originally collected for an investigation. This type of data is original in character because they are collected by field workers; enumerate investigators for the first time for their own use.

For instance, data obtained population census by the office of the Registrar General, Census Commissioner, Minister of Home Affairs are termed as primary data. To quote Wessel, “Data origin; collected in the process of investigation are known as primary data”.


However, some examples will make us clear the meaning of primary data. Suppose, we study the height of students of Class IX of D.A.V. School, Bhubaneswar.

For this purpose, we shall approach each and every student of the class and about his height. Therefore, this collected data will be termed as primary data.

Suppose, we study the labour productivity of Punjab and Orissa.

For this purpose approach the selected labourers in both states and ask productivity. It will also be termed as primary data.



(i) Degree of accuracy is quite high.

(ii) It does not require extra caution.

(iii) It depicts the data in great detail.


(iv) Primary source of data collection frequently includes definitions of various! and units used.

(v) For some investigations, secondary data are not available.


(i) Collection of data requires a lot of time.


(ii) It requires lot of finance.

(iii) In some enquiries it is not possible to collect primary data.

(iv) It requires a lot of labour.

(v) It requires a lot of skill.