ABSTRACT
This chapter describes the concept of t test as a test of the difference between two sample means to determine statistical difference. It discusses the factors affecting the probability level that the null hypothesis is true, and determines the difference among independent samples, paired samples, and one sample t tests. The chapter deals with how to compare two sample means for statistical significance. When the t test yields a low probability that a null hypothesis is correct, researchers usually reject the null hypothesis. A new statistical notation needs to be introduced in this context of means comparison. The degrees of freedom count the number of independent pieces of information used for the result (N) minus the number of groups.
