This chapter discusses the use of questionnaires as a method of data collection, including a brief introduction to internet-based questionnaires. Some of the advantages and disadvantages of using questionnaires in a research project are outlined. Issues of questionnaire design and administration are explored, including a description of some of the most commonly used question formats. Common problems in questionnaire design are presented, and the importance of conducting a pilot study is discussed. The chapter concludes with a discussion of the use of questionnaires in collecting qualitative data.