This tutorial is an optional supplement designed to enhance the courseware of PSYC 304 (Research Methods in Psychology) offered by the Centre for Social Sciences - Psychology of Athabasca University. It was authored by Dr. Janine Keown-Gerrard with general direction from Dr. Cheuk Ng. Web design was provided by Lorna Brown. This tutorial is modelled on the Internal Validity tutorial authored by Dr. David Polson of Athabasca University.


Part 1 of this tutorial contains an overview of simple between and within-subject designs along with a number of examples. Advantages and disadvantages of the designs are highlighted.

In Part 2, a number of experiments are described for you. You are required to indicate the type of experimental design (between or within), identify the dependent and independent variables, and indicate the particular levels of the independent variable, how well the independent variable was manipulated, and how the dependent variable was measured.


Following many of the vignettes in Part 2 of this tutorial, a reference is made to a Related Source. This reference is included for students interested in pursuing the subject matter of the vignette. Sometimes the details of the experiment outlined in the vignette are very similar to the Related Source, but in other cases they are quite different. Thus, the experiment as presented is not to be regarded as an accurate description of the Related Source-the commonality between the two may simply be similar independent and dependent variables.