Bill Verplank is interviewed by Bill Moggridge about Interaction Design. His illustrated descriptions clarify the pioneering interaction design work of Bill Atkinson and Larry Tesler. Combine these interviews with the ideas of David Liddle, Terry Winograd and Gillian Crampton Smith for an overview of the subject.
Bill says that the interaction designer needs to answer three questions, about how people act, how they feel, and how they understand. He illustrates the answers as he talks.