What is Statistical Hypothesis Testing?
Four basic steps constitute statistical hypothesis testing. First, one develops a null hypothesis about some phenomenon or parameter. This null hypothesis is generally the opposite of the research hypothesis, which is what the investigator truly believes and wants to demonstrate. Research hypotheses may be generated either inductively, from a study of observations already made, or deductively, deriving from theory. Next, data are collected that bear on the issue, typically by an experiment or by sampling. (Null hypotheses often are developed after the data are in hand and have been rummaged through, but that’s another topic.) A statistical test of the null hypothesis then is conducted, which generates a P-value. Finally, the question of what that value means relative to the null hypothesis is considered. Several interpretations of P often are made. Sometimes P is viewed as the probability that the results obtained were due to chance. Small values are taken to indicate that the results
