Knowledgeable and unbiased observers have generally noted, and studies have reliably shown, that psychotherapy is better than no treatment at all for a person who is seriously depressed. My study failed to find a difference. From this I can conclude that
A) psychotherapy really is not effective.
B) my study must have been poorly done.
C) my study may have lacked sufficient power to find a difference.
D) other psychologists don't know what they are talking about.

Question

Quizplus · Accepted Answer

The fact that other studies have shown psychotherapy to be effective, combined with the failure of this study to find a difference, suggests that this study may have lacked sufficient statistical power to detect a difference. This could have been due to a number of factors, including small sample size or inadequate measurement tools. Therefore, it is unlikely that psychotherapy is completely ineffective, and it is more likely that the results of this study were limited by methodological factors.

Knowledgeable and Unbiased Observers Have Generally Noted, and Studies Have