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, then the researcher should find ______.
A)a sample mean difference near zero
B)a t statistic near zero
C)the variance of the difference scores is near zero
D)None of the other options is correct.

Question

Quizplus · Accepted Answer

If all participants show a consistent improvement of 8 or 9 points, the variance of the difference scores will be near zero because there is little variability in the scores.

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