A researcher uses a repeated-measures design to compare individuals' performance before treatment with their performance after treatment.If all of the participants show improved performance of 8 or 9 points after treatment,what should the researcher find?
A)The sample mean difference is near zero.
B)The t statistic is near zero.
C)The variance of the difference scores is near zero.
D)None of the other options is correct.

Question

Quizplus · Accepted Answer

The variance of the difference scores is near zero because all participants show similar improvement, indicating little variability in the difference scores.

A Researcher Uses a Repeated-Measures Design to Compare Individuals' Performance