Inferring the alternative hypothesis: Risky business

Unlike the null hypothesis, the alternative hypothesis has been given little methodological attention by social scientists. It is argued that for a complete understanding and appreciation of hypothesis-testing, the nature of the alternative hypothesis must be thoroughly studied. Inferences based on rejecting the null hypothesis are inadequate if an inappropriate alternative is inferred. Examples of inappropriate inferences are discussed from the areas of psychology, cosmology, medicine, education and chance to highlight the generality of the problem. The primary purpose of the article is to stimulate thought about the alternative hypothesis by considering: 1) differences between the conceptual and statistical alternatives; 2) the construing of the alternative and; 3) how to best characterize the alternative hypothesis. It is concluded that it is best characterized as a "next best guess explanation" given a rejected null hypothesis.