The first published account of the theorizing that was involved in the development of John M. Keller’s ARCS model is contained in a 1979 publication entitled Motivation and Instructional Design: A Theoretical Perspective. At that early stage, Keller explains his working definition, “motivation is generally defined as that which accounts for the arousal, direction, and sustenance of behavior” (Keller, 1979, p. 29). The emergence of Keller’s model was heavily influenced by a research into a variety of underlying motivational constructs. The theoretical alignment of the original ARCS model is covered more in-depth in the theoretical alignment section. The ARCS model has an official website. This textbook explores the ARCS model.