Something that I've observed about teaching, particularly when it comes to climbing, is that a beginner can really only absorb 3-4 key points at a time. I watched this year as someone attempted to give a 30-minute crash course on everything climbing. Subjects included knots, rapping, anchors, cams, nuts, bolt placement, belaying, and a number of very interesting situations which cause one to act in some way contrary to a 'rule-of-thumb'. Afterwards, I asked a few of the people crowded around what they retained from the little session. The answer was 'nothing'.
Shawn and Steve make a good case for a long period of learning whereby an inexperienced person can be taught to identify proper action through situational expereince. The apprenticeship model. That's indeed the best case but guess what... I see very little of that going on around here.
Many people today are getting their climbing education from a 2 day course, a book, or reading something online. If that's all they're getting and I've got limited ability to explain the dozens of complexities out there... I'll stick with the rule of thumb that works 99 times out of 100... especially when the 1 time it doesn't work isn't likely to get you killed. I've still not read a good reason to stop preaching knots.
Shawn B wrote:
Since this seems to be a multi topic thread with a "safety" theme, I'm curious to those who insist on knots in the end of yer ropes, what type of anchor do you use for sport climbing? A draw to each bolt? Or locker to each bolt, equalized and redundant webbing/cordelette and two o&o lockers on the rope end? Knowing the answer, why so adamant about the knots?

I use and teach the latter.
I hope you are also teaching them how to ascend the rope after they have rapped to the knots.