The construction of an interview schedule or questionnaire is a time consuming task requiring considerable attention to all the details. The investigator must make many decisions, including whether to use an interview schedule or a self administered questionnaire as well as how to balance open-ended and close-ended questions.
Researcher generally works with an outline of the instrument if it is complex and encompasses a variety of topics. Questions for relevant content area are then drafted or borrowed or adapted from other instruments. Researcher must carefully monitor the wording of each question for clarity, sensitivity to the respondent's psychological state, freedom from bias and reading level. Questions must then be sequenced in a psychologically meaningful order and in a manner that encourages'cooperation.
When the instrument has been drafted, it should be critically reviewed by experts, and pre-tested with a small sample of respondents. Pre-test. is a trial run to determine insofar as is possible whether instrument is clearly worded and free from bias