Stephen Downes

I remember commenting quite critically on the sliders Jay Cross used to illustrate degrees of formal and informal learning; my objection was that they suggested a compromise position could be reached in what was essentially an on-off factor (for example, when student need and institutional goals contradict, either student or institution wins; there is no middle way). But the diagram was useful in illustrating that the definition of 'informal' is multi-facted; there isn't this thing, 'informal', that you could measure. The same criticism, and the same observation, holds of this slider-model of problem-based learning. PBL isn't jut one thing; it's a set of methods and assumptions, each of which may be necessary for full problem based learning.