The present study extended multimedia learning principles beyond the lab to an ecologically valid setting (homework). Eighteen information cards were used to perform three homework tasks. The control group students learned from single representation (SR) cards that presented all information as printed text. The multiple representation (MR) group students received the same information, but each card contained either printed text or an informationally equivalent graphic such as a chart or graph. The MR group students performed better than the SR group students on accuracy of their homework answers and on subsequent post-test retention and transfer, and used more information cards while learning. The improved MR group students' performance is discussed in relation to two alternative possible explanations: the nature of the information sources and students' motivation to learn. (Contains 3 tables and 1 figure.)