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 In the first of these excerpts, notice that the researchers state that their findings had "practical significance as well as statistical significance." In Excerpt 8.2, note that the researchers point out that their findings lack practical significance despite the fact that their data produced statistically significant results. It would be nice if all research reports contained statements like the ones in these two excerpts. Unfortunately, many researchers seem concerned with just one thing: statistical significance. This is dangerous because it is quite possible (as illustrated by Excerpt 8.2) for a study's results to be significant in a statistical sense without being important (i.e., significant) in a practical sense.
1The terms clinical significance, used frequently within medical research, means the same thing as practical significance.
(From Chapter 8, pp. 180-181)
Copyright © 2012
Schuyler W. Huck