Have students go to the library and find an article where the researcher articulates the reason for using one measure rather than another. Have students explain the author's logic to their group or to the rest of the class.
To help students with the assignment, you might tell them that the explanation will probably be in either the introduction or the method section. In addition, suggest that they will probably have the most success if they choose a study that involves measuring some rather general concept (depression, intelligence, aggression, etc.).
An alternative to going to the library is to have students debate the choice of measures used in the sample paper (Appendix C). Frank and Gilovich do an exceptional job of explaining why they chose the measures they did. It is important for students to understand those reasons. However, it is also nice for students to recognize the weaknesses of those measures.