A critical analysis of various methods of collecting primary data is as follows :
- Direct personal investigation method : Though the information collected thought this methods is original, authentic, homogeneous and inelastic, Yet this method suffers from some flaws like the researchers can get personally biased which can affect the results. As a result of working in a specific and limited area, the results can become biased.
- Indirect oral investigation method : Here, the data is not directly associated with the researchers. It is collected indirectly, and thus, witnesses from whom the information is obtained may be careless also.
- Information through local residents and correspondents : In this method, the information is sent by experience. If the experience of a source is lacking, or the researcher is new, then correct data is not received. There are many impurities in this method.
- Information through filling of questionnaires by informant : In this method, if the informant is not literate then he cannot correctly fill the questionnaire. With the fear of indirect and incomplete information, it also contains possibility of incomplete purity and negligence.
- Information through enumerators : This method is very expensive, it creates the problem of training and delay in contact. Incorrect information can also be given by the information provider to the enumerator, due to which the schedule may be filled incorrectly.
