In this essay, William Gaver explores the nature and development of research through design (RtD) in the context of Human-Computer Interaction (HCI). He reviews two influential theories from the Philosophy of Science to reflect on the nature of design theory, concluding that RtD is likely to produce theories that are provisional, contingent, and aspirational. Gaver discusses three interpretations of the diversity of approaches to RtD, suggesting that this variation is natural for a generative endeavor and should not be seen as a sign of inadequate standards or lack of cumulative progress. He argues that practice-based research might better view theory as annotation of realized design examples, particularly portfolios of related pieces. Overall, Gaver suggests that the design research community should be wary of impulses towards convergence and standardization, and instead take pride in its ability to explore, speculate, particularize, diversify, and manifest results in the form of new, conceptually rich artifacts.In this essay, William Gaver explores the nature and development of research through design (RtD) in the context of Human-Computer Interaction (HCI). He reviews two influential theories from the Philosophy of Science to reflect on the nature of design theory, concluding that RtD is likely to produce theories that are provisional, contingent, and aspirational. Gaver discusses three interpretations of the diversity of approaches to RtD, suggesting that this variation is natural for a generative endeavor and should not be seen as a sign of inadequate standards or lack of cumulative progress. He argues that practice-based research might better view theory as annotation of realized design examples, particularly portfolios of related pieces. Overall, Gaver suggests that the design research community should be wary of impulses towards convergence and standardization, and instead take pride in its ability to explore, speculate, particularize, diversify, and manifest results in the form of new, conceptually rich artifacts.