Performance of the Traditional Pooled Variance t-Test against the Bootstrap Procedure of Difference Between Sample Means

In this study, two methods of comparing the means of two samples were conducted. The first method used the traditional pooled variance t-test while the second method used the bootstrap method of comparing means. In the second method, pseudo sampling distributions were generated for the normal and non-normal distributions. For the non-normal we used the and a g=.5, h=.5 distribution. Group sizes {5, 15} and {15, 25} with equal and unequal variances were generated and for each method Type I error rates were evaluated. We found that about 20% and 33% of the study conditions using the pooled variance t-test were robust when group sizes are {5, 15} and {15, 25}, respectively. Whereas, about 33% and 47% of the study conditions in bootstrapped procedure were robust when group sizes are {5, 15} and {15, 25}, respectively.