General Considerations
The main functions of questionnaires are to extract information from respondents, record and process it. To achieve this effectively, a questionnaire should:
provide clear instructions (for respondents, interviewers and processors);
clearly and concisely define what is to be collected and recorded;
maintain respondents' cooperation and involvement;
enable respondents to complete it accurately and within a reasonable time;
use a language that is understood by the respondents;
avoid bias in question wording;
make the job of the respondent and/or interviewer easy;
appear uncluttered on the form;
provide suitable space for responses; and
be easily processed by both people and machines.
be in a suitable form for keeping as a hard copy record.
Additionally, it is necessary to realise that a questionnaire often cannot provide all the information that a client would like to obtain. If a questionnaire becomes too long or confusing, respondents may be unwilling to complete it, or they may make mistakes.