This document discusses the purpose and types of questionnaires. It explains that questionnaires are forms used to collect responses to questions from a sample of people. There are different types of questions like closed-ended and open-ended, and questions can collect facts or opinions. Properly designing questionnaires is important, including clear instructions, question order, and coding responses for analysis. Questionnaires can efficiently collect standardized information from many people but also have limitations like potential bias and unreliable responses.