What opportunities does virtual reality offer to improve the way we learn? In this thesis, I investigate the ways that constructivist approaches, in particular exploratory and experiential learning, can be uniquely supported by immersive virtual worlds. Against the background of these learning theories, I introduce a design framework that centers around defining a medium of virtuality that is fundamentally social, and uses capture of movement and interaction as a key means for creating interactive scenarios and narrative. Within the world conjured by this medium, the Equipped Explorer learns, reviews, creates and communicates using tools that I propose and classify according to a taxonomy. A series of prototypes and design explorations are used as proofs of concept for aspects of the design framework. Experimental studies are used to investigate foundational questions concerning the learning benefits of using VR over 2D interactive media, and the viability of social interaction and collaboration in VR. I reflect on the implications of this framework and my experimental results to extrapolate how they might impact the future classroom and the practice of learning and discovery more broadly. Finally, I discuss what kinds of research might be needed to maximize that impact moving forward. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu).