ABSTRACT
The questionnaire is an important component of a poll. It is a measuring instrument that is used for collecting and recording data. This chapter expresses that a lot can go wrong in the process of asking and answering questions. Therefore, it is import to test a questionnaire. It is often not clear from the documentation whether the questionnaire was really tested, and how it was tested. The chapter presents a number of aspects that can be checked. The results of these checks should help us to judge the questionnaire. The question must exactly define the fact it intends to measure. Experience has shown that even a small change in the question text may lead to a substantially different answer. Nonfactual questions ask about attitudes and opinions. An opinion usually reflects a view on a specific topic, like voting intention for the next election. An attitude is a more general concept, reflecting views about a wider, often more complex issue.
