Questionnaires can be thought of as a kind of written interview. They can be carried out face to face, by telephone, or post
The choice of questions is important because of the need to avoid bias or ambiguity in the questions, ‘leading’ the respondent or causing offence
Open questions are designed to encourage a full, meaningful answer using the subject’s own knowledge and feelings. They provide insights into feelings, opinions, and understanding. Example: “How do you feel about that situation?”
Closed questions can be answered with a simple “yes” or “no” or specific information, limiting the depth of response. They are useful for gathering specific facts or confirming details. Example: “Do you feel anxious in crowds?”
Its other practical advantages are that it is cheaper than face-to-face interviews and can be used to contact many respondents scattered over a wide area relatively quickly