A medical journal published the results of an experiment on anxiety. The experiment investigated the effects of a controversial new therapy for anxiety. Researchers measured the anxiety levels of 91 adult women who suffer moderate conditions of the disorder. After the therapy, the researchers again measured the women's anxiety levels. The differences between the the pre- and post-therapy anxiety levels were reported. What type of experimental design is this?
A) completely randomized design
B) randomized block design
C) single-blind design
D) matched-pairs design

Question

Quizplus · Accepted Answer

This is a matched-pairs design because each participant serves as her own control, with anxiety levels measured before and after the therapy, allowing for direct comparison of the effects of the therapy on the same individuals.

A Medical Journal Published the Results of an Experiment on Anxiety