Designing a questionnaire
In a survey, the researcher uses a questionnaire to gather information from the respondents to answer the research questions. A questionnaire is a very convenient way of collecting information from a large number of people within a period of time. Hence, the design of the questionnaire is of utmost importance to ensure accurate data is collected so that the results are interpretable and generalisable. A bad questionnaire renders the results uninterpretable, or worse, may lead to erroneous conclusions.
A survey can come in many forms: postal survey, telephone interviews, face-to-face interviews and internet surveys. Each type of survey requires a slightly different design. A self-administered questionnaire (e.g. postal survey) should have very clear instructions and questions, follow a logical order and avoid complex filtering. The respondents are more likely to answer truthfully without prompting from an interviewer. On the other hand, in an interviewer-administered questionnaire (e.g. face-to-face interview or telephone interview), the questions can be more complex as they can be clarified by the interviewers. However, the presence of an interviewer may “pressurise” the respondents to give “appropriate” rather than truthful answers. (copied from article)