Distinguish between primary data and secondary data.
Following are the main differences between primary and secondary data:
(i) Primary data is collected by the investigator himself. It is original and first-hand information. On the other hand, secondary data is already available in published or unpublished form. It is not original in nature.
(ii) Primary data is always collected in order to meet a specific objective. It does not need any adjustment or modifications. On the other hand, secondary data is the data which has already been collected for some objectives. So, it has to be adjusted and modified to suit the objective of the study.
(iii) Collection of primary data requires a lot of time, money and effort because it is collected by the investigator himself. On the other hand, secondary data is obtained either from published sources or from any other sources like websites. Therefore it is less expensive. It also saves time and cost.
(iv) No precautions are required in the use of primary data whereas precautions should be taken while using secondary data.