This paper describes a framework for making explicit the design decisions in the development of immersive and interactive STEM learning technologies. This framework consists of three components: (1) "visual viewpoint," the location from which a visual simulation depicts observable components; (2) "embodied interaction," the ways in which a learner can physically engage with the simulation interface; and (3) "learners' roles," the purpose and the participation structure the technology presents to the learner. The recent literature on the design of STEM learning technologies is reviewed with the lens of how the three components have been leveraged and what, if any, rationale is provided for the design decisions that were made. The definition and review of each component is followed by a set of reflective questions intended to prompt researchers and designers to be more explicit about these decisions and the ways they are intended to impact student learning in both the design process and the reporting of their work. The paper concludes with a discussion of how the three components interact, and how their articulation can support theory building as well as the proliferation of more effective STEM learning technology designs.