The chapter, "Activity theory and context: An understanding of the development of constructivist instructional design models" was written by the listed authors including Laura G. Farres (Douglas College Faculty). Constructivist instructional design (ID) models have emerged with more frequency within e-learning. These models offer guiding principles congruent with constructivist approaches to teaching and learning. Although constructivist ID models share common principles, each model also offers a unique approach to e-learning based on its context of development. Consequently, certain models will also be more authentic and meaningful for a particular situation depending on their compatibility to that particular context. If that context can be understood, then direction can be given as to the best application for the model. This chapter introduces activity theory (AT) as a lens from which to understand the context of constructivist ID model development in e-learning. It argues that AT provides a suitable frame-work for naturalistic inquiry within complex settings and establishes a language from which a better comparison of context can occur.