It often is possible to reduce the variance in an independent-measures design by using a participant variable such as age or gender as a second factor.

Question

Quizplus · Accepted Answer

Including a participant variable as a second factor in an independent-measures design can result in a more homogeneous sample, reducing the variance in the data. For example, if age is used as a participant variable and participants are assigned to groups based on age, then age-related differences that could confound the results are minimized.

It Often Is Possible to Reduce the Variance in an Independent-Measures