Each of the following bolsters confidence in the obtained results of an experiment, EXCEPT:
A) researchers find a significant difference between the control and experimental groups on the manipulation check.
B) the investigation reveals a significant difference between groups on preexisting differences.
C) statistical analyses reveal a moderate effect size.
D) the investigation fails to reveal significant differences between groups on preexisting characteristics.

Question

Quizplus · Accepted Answer

Finding a significant difference between groups on preexisting differences suggests that the groups were not equivalent at the start of the experiment, which could confound the results. This does not bolster confidence in the obtained results, unlike the other options which indicate methodological rigor or meaningful effects.

Each of the Following Bolsters Confidence in the Obtained Results