Now comes the task of designing the questionnaire. Questionnaires must be short and concise .
Too many questions bore the responder and can induce wrong answers just to annoy back the interviewer.
If the question is not going to be used in the analysis, why ask them in the first place?
Open questions are difficult to code.
Multiple choice can induce the answer, can lead to bias.
Yes/No questions limit the scope of the responses.