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 Excerpt 8.1, notice that the researchers argue that "beyond statistical significance," their finding appeared to be "of considerable practical significance as well." In Excerpt 8.2, the researchers first note that they had a giant sample size; then, they warn their readers not to automatically equate statistical significance with practical significance. It would be nice if all research reports contained statements like the ones in these two excerpts (or like the statement we saw earlier in the final excerpt of Chapter 7). Unfortunately, many researchers seem concerned with just one thing: statistical significance. This is dangerous because it is quite possible for a study's results to be significant in a statistical sense without being important (i.e., significant) in a practical sense.
1The term clinical significance, used frequently within medical research, means the same thing as practical significance.
(From Chapter 8 in the 6th edition, pp. 162-163)
Copyright © 2012
Schuyler W. Huck