This chapter presents and problematizes a theoretical design framework for understanding and supporting teachers’ pedagogical reasoning in online contexts. The framework synthesizes existing educational theories to illustrate how digital technologies can be used to create interactional and aligned educational designs and is therefore referred to as the IAED framework. The IAED framework can be used in teacher education and development programs, and by teachers, researchers, educational designers and others. In the chapter empirical examples and analysis are provided to illustrate and discuss how the IAED framework can be used to: (a) support teachers’ pedagogical reasoning and educational design practices, (b) evaluate existing educational designs and design practices, and (c) study educational designs and design practices, as well as (changes in) teachers’ pedagogical reasoning.