In a nonrandomized control group, pretest-posttest design, the recommended procedure for analyzing test results is a(n)
A) t-test of the difference between pretest and posttest means for both the experimental and the control group.
B) four-way analysis of variance.
C) analysis of covariance, in which the posttest means are compared using the pretest means as the covariate.
D) analysis of variance of the mean pretest-posttest change for the experimental and control groups.

Question

Quizplus · Accepted Answer

The analysis of covariance (ANCOVA) is the recommended procedure for analyzing test results in a nonrandomized control group pretest-posttest design, as it allows for the pretest scores to be used as a covariate in the analysis. This means that any pre-existing differences between the groups can be accounted for, allowing for a more accurate assessment of the treatment effect. The other options, such as t-tests, ANOVA, or four-way ANOVA, may not fully account for pre-existing group differences and may not provide as accurate results.

In a Nonrandomized Control Group, Pretest-Posttest Design, the Recommended Procedure