Identifies and summarizes instructional messages in the articles in this theme issue and also identifies central theoretical issues, focusing on: (1) external representations; (2) dual coding theory; and (3) the effects of animations on learning. (SLD)

The terms dynamic representation and animation are often used as if they are synonymous, but in this paper we argue that there are multiple ways to represent phenomena that change over time. Time-persistent representations show a range of values over time. Time-implicit representations also show a range of values but not the specific times when…

Studied the selective processing of information in dynamic graphics by 12 undergraduates who received training aided by animation and 12 who did not. Results indicate selective processing of the animation that involved perceptually driven dynamic effects and raise questions about the assumed superiority of animations over static graphics. (SLD)