Recent developments in computer technology provide exciting, innovative ways of representing and interacting with information, bringing new perspectives on learning with multimedia. Animated diagrams are one form of (graphical) representation being increasingly used in multimedia contexts, with underlying assumptions about their educational benefits. Previous research suggests that diagrams can facilitate understanding, as information is more visually explicit, requires less inference recognition than sentential representations, and constrains inferences, which can guide cognitive processing. Thus, the visual explicitness of motion inherent in an animated diagram should also reduce cognitive processing and aid understanding of dynamics. However, facilitation of cognition results from particular properties integral to the static representation, and although some of these properties may apply to animated diagrams, research suggests that underlying differences in the fundamental form of an animated representation, may generate different cognitive outcomes, making these benefits less apparent. This research focuses on cognitive interaction with animated graphics by investigating the effects of fundamental properties of animation on cognition. A comparative study using animated and static graphics of a dynamic system, is used as a basis for collecting information about potential learning models and properties specific to animated representations. Three groups of properties are identified, and a model of learning with an animated diagram in relation to these graphical properties is proposed. With these perspectives as a basis, a series of studies investigates the cognitive interaction needed with an animated diagram by pupils studying dynamic processes. The results from these studies suggest that initial assumptions about the cognitive benefits of animation are unclear, but they do show evidence of patterns in cognitive processing of dynamic information. This provides the basis for generating a preliminary cognitive model for processing graphical change from animated diagrams. This model serves as a starting point for further research and for informing particular aspects of diagram design.