Consider a 2 X 2 Experiment Design in Which Both

Multiple Choice

Consider a 2 x 2 experiment design in which both study time and sleep time have been manipulated and learning has been measured. If a main effect of sleep time is found, this can be interpreted to mean which of the following?

A) Sleep time affects learning, controlling for study time.
B) Study time has no effect on learning.
C) Study time and sleep time both influence learning.
D) The interaction between study time and sleep time is not significant.