The Importance of the Null Hypothesis

Although the journey of hypothesis testing ends with an important decision, you should keep in mind that this final decision always has reference to the point of departure. Researchers never end up by rejecting (or failing to reject) "in the abstract"; instead, they always will terminate the hypothesis testing procedure by rejecting (or failing to reject) a specific Ho. Accordingly, no decision to reject should be viewed as important unless we consider what specifically has been rejected. On occasion, the hypothesis testing procedure is used to evaluate a null hypothesis that could have been rejected from the very beginning, strictly on the basis of common sense. Although it is statistically possible to test such a Ho, no real discovery is made by rejecting something that was known to be false from the outset.

We cannot exaggerate the importance of the null hypothesis to the potential meaningfulness of results that come from someone using the hypothesis testing procedure. Remember that a "reject" decision, by itself, is not indicative of a useful finding. Such a result could be easily brought about simply by setting up, in Step 1 [of the hypothesis testing procedure], an outrageous Ho. Consequently, you should always be interested in not only the ultimate decision reached at the end of the hypothesis testing procedure but also the target of that decision--Ho.

(From Chapter 7, pp. 198-199)

Copyright © 2003 Schuyler W. Huck
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