Workshop on ACT-R Models of Human-System Interaction, Mesa, AZ, January 2002.

Simulating the effects of behavior moderators within a cognitive architecture is essential for building cognitive models that can realistically capture the full range of human performance. We demonstrate that some of these effects can be modeled by varying parameters of the cognitive architecture and some by modifying the knowledge that is built into the models. As an example of implementing the two approaches, we present an ACT-R model that performs serial subtraction under varying levels of task-appraisal and with and without anxiety realized as worry