Interview Method:

• In this method, the investigator goes from house to house and interviews the individuals personally. This method helps to develop the relationship between interviewer and the interviewee which increases mutual understanding between the parties. It is less costly.
• It is time-consuming. It has the possibility that it can be influenced by the biases of the interviewer.

Mailed Questionnaire method:

• It is less costly and not time-consuming.
• It is practicable only among the educated people who are really interested in the particular survey being conducted.