Advantages of Questionnaires:
1. As an instrument of data collection the questionnaire has great potentialities when it is properly used.
2. It is economical both for the sender and for the respondent in time, effort and cost.
3. It is easy to plan, construct and administer.
4. When the subjects of the study are scattered far and wide, it will be a better tool as compared to the tools like interview. It permits nationwide or even international coverage.
5. It permits group administration and is adaptable to any objectives.
6. It is generally regarded as dependable when used to obtain statement of fact.
7. Information of a personal nature often may be obtained more readily by means of questionnaires.
8. It places less pressure on the subject for immediate response.
9. It helps in focusing the respondent’s attention on all the significant items. It does not permit much of variation.
10. It may be used as a preliminary tool for conducting indepth study later on by any other method.
11. The responses given by the subjects are available in their own language and version.
Limitations of Questionnaires:
1. Its reliability and validity is low. It seeks secondary information concerning facts when primary evidence is not at hand.
2. Frequently questionnaire research constitutes simply a pooling of ignorance. It is compilation of the opinions of many persons who may not know the answer.
3. It gives a biased sample. The matter of non-response is always a big question mark.
4. The respondents who return the questionnaires may not constitute a representative section of the entire group.
5. If the subject misinterprets a question or gives an incomplete or indefinite response, nothing can be done.
6. A questionnaire is more or less rigid in its structure about complex emotional subjects.
7. Some respondents may not like to put their views on controversial issues in writing.
8. The behaviours, gestures, reactions, emotions of the respondent remain unnoticed.
9. Some of the research areas are so delicate, sensitive and confidential in nature that it becomes difficult to frame questions on them.
10. The questionnaire cannot be used with illiterate subjects and children.