The questionnaire is a formal approach to measuring characteristics, attitudes, motivations, opinions as well as past, current and possible future behaviours. The information produced from a questionnaire can be used to describe, compare or predict these facts. Depending on the objectives, the survey design must vary. For instance, in order to compare information, you must survey respondents at least twice. If you are comparing travel intentions and travel experience, you would survey respondents before they leave on vacation and after they return to see in which ways their perceptions, opinions and behaviours might have differed from what they thought prior to experiencing the destination.
Everything about a questionnaire – its appearance, the order the questions are in, the kind of information requested and the actual words used – influences the accuracy of survey results. Common sense and good grammar are not enough to design a good questionnaire! Indeed, even the most experienced researchers must pre-test their surveys in order to eliminate irrelevant or poorly worded questions. But before dealing with the question wording and design and layout of a questionnaire, we must understand the process of measurement.