ANOVA with Two Within-Subject Variables (1 of 3)
Consider the following hypothetical experiment: A total
of four rats are run in a maze three trials a day for two days. The
number of wrong turns on each trial are shown below.
Sources of Variation
The sources of variation in this design are: Subjects, Days, Trials,
the Days x Trials interaction, and Error. The ANOVA summary table is
shown below. Notice that there are three error terms: one for the
effect of Days (MSE = 1.38), one for the effect of Trials (MSE =
0.61), and one for the interaction (MSE = 0.17).