If a researcher suspects that the strength of the relationship in the population is .25 for the main effect of factor A,.03 for factor B,and .15 for the interaction effect as indexed by eta-squared,what sample size should she use per cell in a study involving four levels of factor A,two levels of factor B,and an alpha level of .05 in order to achieve a power of at least .95 for each effect?
A)7
B)12
C)25
D)53
E)211

Question

Quizplus · Accepted Answer

Using G*Power software, the sample size calculation for a 4x2 between-subjects ANOVA with three main effects, an interaction effect, alpha level of .05, and power of .95 yields a total sample size of 212 participants. Thus, using equal cell sizes, the number of participants per cell would be 53.

If a Researcher Suspects That the Strength of the Relationship