Speculative and fictional approaches have long been implemented in human-computer interaction and design techniques through scenarios, prototypes, forecasting, and envisionments. Recently, speculative and critical design approaches have reflectively explored and questioned possible, and preferable futures in HCI research. We propose a complementary concept – material speculation – that utilizes actual and situated design artifacts in the everyday as a site of critical inquiry. We see the literary theory of possible worlds and the related concept of the counterfactual as informative to this work. We briefly present three examples of interaction design artifacts that can be viewed as material speculations.