Ruth Colvin Clark has worked for more than twenty-five years with instructional professionals assigned to design, develop, and select effective training for classroom or computer delivery. She is widely published in the areas of training, development, and performance improvement.

Richard E. Mayer is professor of psychology at the University of California, Santa Barbara. He is an internationally-recognized expert in the application of learning psychology to design of instruction in multimedia learning environments and the author of Multimedia Learning and is the editor of the Cambridge Handbook of Multimedia Learning.