Virtual reality (VR) technology is an increasing portion of the consumer technology market. VR technology is being used to treat PTSD, to create virtual worlds for users to explore, and to help teach students advanced visual concepts. Further, VR is a fruitful area for the focus of information science research. Researchers have begun to explore running simulated laboratory experiments in VR and conduct virtual usability tests. Prior work has typically considered "virtual reality" to be any experiences that are created by a tool, marketed as a VR product. However, such product-driven definitions of virtual reality may limit our ability to study and innovate within this field. As such, in this poster we present a work-in-progress study in which we extract information regarding the advancement of goals for VR, components of virtual experiences, and definitions of VR obtained from a body of academic literature and marketing materials for VR products from the 1960s through today. We use an affinity diagramming analysis to distill a comprehensive set of definitions for VR from this data. In future work, we will collect users' definitions of VR to further empirically inform our understanding of what makes up a VR. Such an understanding can serve as the foundation for future research and innovations in VR.