One useful framework for understanding and articulating instructional design to change biased beliefs is the Martin and Reigeluth model for affective development, appearing in Volume II of Reigeluth's "Instructional-Design Theories and Models" (1999). Using this recently developed framework to examine a Web-based multimedia instructional program aimed at affecting biased beliefs suggested that the addition of activity components and the language of activity theory may have potential to extend instructional theory on affective learning. Consideration of action as both internal and external enhances the model in a way that facilitates design and evaluation of instruction to affect biased beliefs about difference. This paper examines some of the implications of including the concept of activity in the Martin and Reigeluth model for affective development. (Contains 46 references and 8 tables.) (Author/AEF)