Statistical Power of Randomization Tests Used with Multiple-Baseline Designs
Abstract Statistical power was estimated for 3 randomization tests used with multiple-baseline designs. In 1 test, participants were randomly assigned to baseline conditions; in the 2nd, intervention points were randomly assigned; and in the 3rd, the authors used both forms of random assignment. Power was studied for several series lengths (N = 10, 20, 30), several effect sizes (d = 0, 0.5, 1.0, 1.5, 2.0), and several levels of autocorrelation among the errors (p 1 = 0, .1, .2, .3, .4, and .5). Power was found to be similar among the 3 tests. Power was low for effect sizes of 0.5 and 1.0 but was often adequate (> .80) for effect sizes of 1.5 and 2.0.