Advantages of Questionnaire1. It is less expensive than an interview.
2. It needs less ability because with a minor explanation it is sent to the respondent and is distributed by personal effort.
3. A large number of respondents respond at the same time.
4. It is mailed but this is not possible in an interview.
5. With limited sources, data can be collected from a large area whereas this is not possible in case of interview.
6. Because of the impersonal nature, standardized working and order of institutions of the questionnaire provide better knowing of a social condition in a uniform manner.
7. It is more trustworthy for the researcher because of anonymity being maintained and more freedom to express his views.
8. Ample time to answer the questions gives the chances of thinking properly to the respondent.
Disadvantages of Questionnairel. Most of population is illiterate in under developing countries so it cannot be used for illiterate respondents.
2. Its process is often a wastage of time because some respondents send it incomplete.
3. Only 60% questionnaire is received back by mail and only 10% complete these.
4. The respondents derive different meaning from questions and the institution in its questionnaire and this affects uniformity.
5. Facial expressions cannot be noted which is helpful in getting results.
6. Many respondents think that it is wastage of time to respond such questionnaires.
7. Questionnaire is thought of less importance for a research therefore, the respondent gives less attention making the research fail in its objectives.