An experiment evaluating the effectiveness of an intervention for improving attitudes about something finds that the mean posttest score of the experimental group is 70, which is better than the control group’s mean posttest score of 65. The significance level is .05, and the p value is .01. The standard deviation is 5.
-The results certainly are substantively significant.

Question

An experiment evaluating the effectiveness of an intervention for improving attitudes about something finds that the mean posttest score of the experimental group is 70, which is better than the control group’s mean posttest score of 65. The significance level is .05, and the p value is .01. The standard deviation is 5. 
-The results certainly are substantively significant.

Quizplus · Accepted Answer

Statistical significance (p value of .01) does not necessarily imply substantive significance, which depends on the practical importance or effect size of the difference.

An Experiment Evaluating the Effectiveness of an Intervention for Improving