Independent Samples T-Test
Amanda Ross, Victor L. Willson · SensePublishers eBooks · 2017
An independent samples t-test compares the means of two groups. The data are interval for the groups. There is not an assumption of normal distribution (if the distribution of one or both groups is really unusual, the t-test will not give good results with unequal sample sizes), but there is an assumption that the two standard deviations are equal. If the sample sizes are equal or very similar in size, even that assumption is not critical.