Westfall & Young's (1993) results suggest that by combining bootstrap methods with methods based on trimmed means researchers can obtain better Type I error control when testing for treatment group equality. Thus, the methods due to Alexander & Govern (1994), Box (1954), and Welch (1951) were compared under conditions of non-normality and variance heterogeneity when group sizes were unequal, conditions known to produce liberal rates of error. We found that, typically, in one-way designs better Type I error control can indeed be obtained when the bootstrap method is used in conjunction with test statistics based on trimmed means.