Let's be very clear. Terry Winograd has a consciously elaborated
theoretical and epistemological framework which is entirely different from
activity theory. Don Norman - if he has a theoretical and epistemological
framework, which I doubt (no offense, Don) - is still mainly rooted in some
version of cognitive engineering paradigm.
Both are surely useful for a student of activity theory. So are thousands
of other books and authors. The fact that Don gives a reference to some
activity-theoretical text or that Terry discusses usability and artifacts
does not make them activity theory.
So let's not inflate activity theory into an unrecognizable balloon of
everything interesting. Let's discuss different approaches acknowledging
their own frameworks and roots.
Cheers,
Yrjo Engestrom