Ecological Cognition in Visualization This effort contributes to the theory of a user model and a measurement methodology designed, in part, to permit quantitative assessment of visualization interfaces. Ecological theory states that the state of affairs in the world can be represented directly through cognitive "states of affairs" (corresponding to ecological processing aspects). This work is to test the hypothesis that ecological processing includes cycles of "envisioning" and "inspection" information processing operations. The difficulty of cognitive tasks can then be characterized by the allocation of processing resources (e.g., the allocation of attention) between the (relatively) memory-independent ecological operations and controlled, memory intensive symbolic processing. Thus, this approach allows consideration of the task context as well as viewing logical cognitive operations. It makes possible testable predications about both abstract and concrete tasks. It can be folded into existing GOMS models for quantitative assessment of interface metaphors allowing subsequent evaluation and minimization of the difficulty of interacting with direct manipulation and visualization interfaces.
