Describe the hypotheses for an independent-measures t test, the structure of the independent-measures t statistic, and explain how it is related to the single-sample t. Discuss the basic assumptions underlying the independent-measures t hypothesis test, especially the homogeneity of variance assumption, and explain how the homogeneity assumption can be tested. Finally, describe how sample size and sample variance influence the outcome of a hypothesis test and measures of effect size for the independent-measures t statistic.