The management of activity settings and the orchestration of assistance to teachers are complex tasks, with endless opportunities for error, delay, confusion, anxiety, and all the other problems that can arise in human social transactions. Cast as a set of propositions about teacher training, the theoretical structure presented thus far has all the advantage of the “schooled” or “scientific” or “systematic” set of concepts – and all the disadvantage: “Propositions are remarkably economical in form, containing and simplifying a great deal of complexity. … They gain their economy precisely because they are decontextualized, stripped down to their essentials, devoid of detail, emotion, or ambience” (Shulman, 1986, P. 11).

The liability of this “schooled” propositional knowledge is its inability to convey how the structures and processes appear and function in concert, in particular circumstances of everyday life (Shulman, 1986, p. 11). In practice, the means and sources of assistance to teachers – in given activity settings – are inevitably concatenated and interpenetrated. Their complexities are further compounded by the personalities of the actors, the particularities of a given school, and other features of the local ecocultural niche. Knowing only the propositions of Chapter 9 would provide little assistance to any who sought to implement them.

Shulman offered one remedy for the liability of propositional knowledge: case knowledge: