A questionnaire, or a schedule is a list of questions framed already to be put before the informants for collecting the data relating to a problem under study. In order that the proper response and appropriate answers may be received from the informants the questionnaire should be properly framed keeping in view the precautions to be taken in regard to a questionnaire discussed earlier. However, before releasing a questionnaire for the real work of collection of the data, it should be put to a preliminary test known as pilot survey to observe the fitness, or otherwise of the questionnaire for the enquiry undertaken. It might so happen that the questionnaire prepared:
- is incomplete in some respect,
- is inadequate for the object of the enquiry,
- contains certain questions which are irrelevant and unnecessary,
- needs clarification to certain concepts and terms used,
- creates confusion in the minds of the informants on some matters,
- contains certain irritative, sentimental and fault-finding questions and,
- is drafted in a language not understandable by the informants.
If the questionnaire full of such defects is released for data collection it will defeat the whole purpose of he enquiry. Such defects should be removed and the questionnaire should be improved in order that the true purpose of the enquiry may be meted out.