The third in a series of three open learning units on research methods for the behavioural sciences. They are suitable either for classroom use or as distance learning material for students working alone and make extensive use of questions, examples, illustrations, self assessment exercises and project work. The units assume no prior knowledge of statistics or of experimental methods, and are suitable for students across a range of behavioural and human sciences, including health care and social work. This third unit looks at drawing inferences from statistical data.