Using the Minneapolis Hot Spots Experiment as an example, the authors identify specific problems investigators might face in documenting displacement effects. They argue that conventional studies are not likely to provide a powerful research design for examining displacement, in part due to efforts to maximize the identification of main program effects. The authors suggest that studies specifically designed for measuring displacement and the related phenomenon of diffusion must be developed if criminologists are to make significant advances in this area. Research must focus on tracking and understanding the nature of the displacement process and not on establishing the efficacy of interventions themselves. 25 references, 4 notes, 1 table, and 1 figure