A questionnaire is a tool for obtaining statistical data from members of the general public or special groups. It consists of a series of questions which usually requires a yes/no or simple multiple choice response. The first questionnaire was invented by Sir Francis Galton. A questionnaire usually requires respondents to enter the data themselves rather than a researcher asking questions through a face-to-face or telephone interview and are therefore much cheaper to acquire.
Questionnaires rely on the respondent being able to read the questions, but are often limited by poorly designed questions which confuse the questionee.