It's been an idea that I've seen used more and more as I've been reading around some of this 'ere teaching literature, and I have to say that it's been an incredibly helpful way for me to think of the subject too. It just makes good intuitive sense of how I approach the material, and honours students' responses to it without allowing a free-for-all. It would definitely be worth getting hold of a copy if you can, although I'm not sure that the mechanics Huston describes would necessarily work in a tutor situation (given that I don't know much about how a tutor situation works).

Noel Entwistle's Teaching for Understanding at University (http://the-lady-lily.livejournal.com/690441.html#cutid1) touches on this idea very briefly, but it's not his main area of interest. Which is a shame, because I'd be very interested to see what a UK-context examination of subject-centered learning looks like, and at the moment I don't know where I'd go to chase that.