Statistical Significance vs. Practical Significance

In Excerpts 8.1 and 8.2 [not shown here], this critically important distinction between statistical significance and practical significance is discussed.1 Considered jointly, the authors of these passages are asserting that many of the studies they reviewed contained results that were trivial in terms of practical implications. This same assertion undoubtedly holds true for research studies conducted in other disciplines, and it also holds true for studies in which the statistical focus is on something other than correlations (e.g., means or proportions). Unfortunately, many applied researchers either don't know or don't heed the warning contained in these excerpts: Large sample sizes can produce a statistically significant result even though there is limited or no practical importance associated with the finding.

1The terms clinical significance and clinical importance, used frequently within medical research, mean the same thing as practical significance.

(From Chapter 8, pp. 180-181)

Copyright © 2003 Schuyler W. Huck
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