There has been an ongoing conversation about the role and relationship of theory and practice in the HCI community. This paper explores this relationship privileging a practice perspective through a tentative model, which describes a “bubble-up” of ideas from practice to inform research and theory development, and an accompanying “trickle-down” of theory into practice. Interviews were conducted with interaction designers, which included a description of their use of design methods in practice, and their knowledge and use of two common design methods—affinity diagramming and the concept of affordance. Based on these interviews, potential relationships between theory and practice are explored through this model. Disseminating agents already common in HCI practice are addressed as possible mechanisms for the research community to understand practice more completely. Opportunities for future research, based on the use of the tentative model in a generative way, are considered.