This article elaborates a production-consumption-mediation paradigm in design history, to examine both the development of design history over the past three decades and the current and future practice of design history, specifically within the UK. While John A. Walker made the case in 1989 for increased design historical attention to be paid to issues of consumption, this article identifies mediation as a third stream in design history, with three prongs: first, the mediation emphasis continues the consumption turn within design history by exploring the role of channels such as television, magazines, corporate literature, advice literature and so on in mediating between producers and consumers and forming consumption practices and ideas about design; second, the mediation emphasis examines the extent to which mediating channels are themselves designed and therefore open to design historical analysisindeed, these channels have increasingly constituted the design historian"s object of study; third, the mediation emphasis investigates the role of designed goods themselves as mediating devices. The identification of the PCM paradigm, and the discussion of the methodological and interdisciplinary issues arising provided here, including the relationship of design history to neighbouring fields, have implications for conceptions of the field of design history, in both content and approach.