OT - Russian orbinauts: I am looking for info on "Activity theory"

[ar81]

I have been told that the criticism of "Usability" of user interfase design premises is that the concept is narrower than
the concept of Activity theory.

http://en.wikipedia.org/wiki/Activity_theory

"Activity theory is a psychological meta-theory, paradigm, or framework, with its roots in the Soviet psychologist
Vygotsky's cultural-historical psychology. Its founders were Alexei N. Leont'ev (1903-1979), and Sergei Rubinshtein
(1889-1960) who sought to understand human activities as complex, socially situated phenomena and go beyond
paradigms of psychoanalysis and behaviorism. It became one of the major psychological approaches in the former
USSR, being widely used in both theoretical and applied psychology, in areas such as education, training, ergonomics,
and work psychology"

I wonder if you could point me to some extra info on that "Activity Theory" (english preferably, for I can't chew russian
yet).

[EtherDragon]

"I have been told that the criticism of "Usability" of user interfase design premises is that the concept is narrower
than the concept of Activity theory."

I'm having a very hard time breaking that sentance down, could you rephrase?