A researcher is comparing a new and less expensive treatment with an established treatment, in hopes of showing that there is no difference in outcome. The researcher does not perform a power analysis and, consequently, selects a sample size that is smaller than what would be recommended for an analysis of variance. The results show that there is no significant difference in outcome between the two treatments. Which type of validity is affected by this?

Question

Quizplus · Accepted Answer

Statistical conclusion validity is affected because the small sample size, due to the lack of power analysis, increases the risk of Type II error (failing to detect a difference when one actually exists), directly impacting the accuracy of statistical conclusions.

A Researcher Is Comparing a New and Less Expensive Treatment