Mainstream discussions of research validity (truth, significance, objectivity) draw heavily on a certain “representational idiom” of science [1] that assumes a knowledge–reality correspondence. However, for research on practices, rather than nature, such a knowledge-reality distinction is neither feasible nor desirable, as it is at odds with the very notion of a “practice”. Drawing on Pickering’s alternative “performative idiom” for science, and extending it to participatory forms of social research, we propose alternative validity claims for practice-oriented research. Using the example of information infrastructuring practices, we show that the three aspects of validity thus reinterpreted become quite closely related to each other and also to the process of information infrastructuring itself. In so doing, we demonstrate the importance of extending the notion of “material agency” to embrace the dual agencies of the practice studied and the researcher’s own disciplinary practice.