Any theory of learning must answer at least four central questions: (1) Who are the subjects of learning, how are they defined and located? (2) Why do they learn, what makes them make the effort? (3) What do they learn, what are the contents and outcomes of learning? and (4) How do they learn, what are the key actions or processes of learning? (p. 133) ... Standard theories of learning are focused on processes where a subject (traditionally an individual, more recently possibly also an organization) acquires some identifiable knowledge or skills in such a way that a corresponding, relatively lasting change in the behaviour of the subject may be observed. It is a self-evident presupposition that the knowledge or skill to be acquired is itself stable and reasonably well defined. There is a competent "teacher" who knows what is to be learned. The problem is that much of the most intriguing kinds of learning in work organizations violates this presupposition. People and organizations are all the time learning something that is not stable, not even defined or understood ahead of time. In important transformations of our personal lives and organizational practices, we must learn new forms of activity which are not yet there. They are literally learned as they are being created. There is no competent teacher. (pp. 137-138)Engeström (2001) i