Statistics: T-Distribution and T-Tests
Review on H ypothesis T esting The objective of the hypothesis testing procedure is to find out whether we can reject the null hypothesis. To reject or not to reject the null hypothesis is a decision made by the researcher. This decision must be based upon an explicitly stated criterion. One has to specify exactly under what conditions that one is willing to reject the null hypothesis. The criterion comes from the research result. It is based upon a critical statistical information from the sample observed. It could be an individual score (if there is one person in the sample, N = 1) or a mean (if there are multiple persons in the sample, N > 1). One wants to create a dilemma between the sample statistic (i.e., the observation) and the null hypothesis. This dilemma or conflict can be represented in terms of probability or likelihood. The researcher wants to show that if the null hypothesis were true, a sample statistic (score or mean) as extreme as the one observed would be...