How can variance be reduced in a between-subjects design?
A) Limit the number of participants in each group.
B) Use a factorial design adding a participant variable (such as age) as a second factor.
C) Reduce the number of treatments.
D) Reduce the strength of the treatment.

Question

Quizplus · Accepted Answer

By adding a participant variable as a second factor in a factorial design, individual differences can be taken into account, reducing the amount of variance that can be attributed to differences between participants. Limiting the number of participants in each group or reducing the number of treatments or strength of the treatment will not necessarily reduce variance in a between-subjects design.

How Can Variance Be Reduced in a Between-Subjects Design