A great collection of papers and even the odd full book by the late great Gordon Pask. His cybernetic theories of learning, especially in the form of conversation theory and the value of teachback in learning, have been very influential (notably through the work of Diane Laurillard) and deserve to be more so. His serialist/holist learning style theory is one of the few that I find even slightly compelling because it actually relates teaching to learning style though, like all the rest of the genre, it makes little sense apart from as a useful reminder that there are infinite different ways to teach the same thing. His systems views of learning are, on the other hand, unequivocally brilliant. Sometimes difficult reading, but the effort pays off.
Address of the bookmark: http://www.pangaro.com/pask-pdfs.html
