The theory of affordances has been widely applied in studies of educational technology. In particular, it has been suggested that different education technologies ‘afford’ different kinds of teaching and learning. In this chapter, we look back to the origin of affordance theory in the work of perceptual psychologist James Gibson. We then offer a brief history of how affordance has been adapted and applied to educational technology. It has been suggested that the concept of affordances is too loose to be useful. This is perhaps because the affordances for action and for thought that any technology has not only depend on the technology, but also on how the user responds to the technology. We discuss the need to design the cultures and norms that shape user responses in addition to designing the technology itself. We offer an example to suggest that affordance theory can be particularly useful for educational design-based research that moves iteratively between the perspective of users and the perspective of the technology.