Design Sensitivity in Criminal Justice Experiments

Interest in randomized experiments with criminal justice subjects has grown, in recognition that experiments are much better suited for identifying and isolating program effects than are quasi-experimental or nonexperimental research designs. Relatively little attention, however, has been paid to methodological issues. Using the statistical concept of power-the likelihood that a test will lead to the rejection of a hypothesis of no effect, a survey examines the design sensitivity of experiments on sanctions. Contrary to conventional wisdom advocating large sample designs, little relationship is found in practice between sample size and statistical power. Difficulty in maintaining the integrity of treatments and the homogeneity of samples or treatments employed offsets the design advantages of larger investigations.