Constructivist instructional design (ID) models have emerged with more frequencywithin e-learning. These models offer guiding principles congruent with construc-tivist approaches to teaching and learning. Although constructivist ID modelsshare common principles, each model also offers a unique approach to e-learningbased on its context of development. Consequently, certain models will also bemore authentic and meaningful for a particular situation depending on their com-patibility to that particular context. If that context can be understood, then direc-tion can be given as to the best application for the model. This chapter introducesactivity theory (AT) as a lens from which to understand the context of constructivistID model development in e-learning. It argues that ATprovides a suitable frame-work for naturalistic inquiry within complex settings and establishes a languagefrom which a better comparison of context can occur.