Well that didn't take long. I got a new book. "Reaching the Animal Mind" by Karen Pryor. Mind-blowing. I want to get a fish, or a hamster, and clicker train it! But I don't have time for another pet, so I will have to settle for my dogs. ;-)
I am working with Elo on learning to let me clip his nails without having to hold him down. I figure, if they can teach elephants to present their feet calmly for maintenance, surely my little biddable cattle dog can do it! (If only his nails didn't grow so fast--the book doesn't say how they take care of these animals in the mean time before they are trained.) I started with straight counter-conditioning. Touch a foot; get a treat, hold a foot; get a treat. It was working, but slow going. A verbal marker helped speed things up a bit more and a clicker was even more effective! Criterion--let me touch your foot without pulling away.
Then I tried something from the book. The book described an experiment in which several dogs were asked to cross novel/scary obstacles (e.g., a pile of rope on the ground). Luring with food had the dogs going around the obstacles, shaping with a clicker and food reward produced faster results, but the fastest results came when the behavior of interacting with the obstacle was marked with a cue for the dog's favorite trick! So you were harnessing the value of not only a single food reinforcement, but also the value of a behavior that has a long history of paying off. I tried it with Elo, reinforcing for not pulling his foot away with a "touch" cue (nose target). After just a couple repetitions of this he immediately seemed more comfortable with the entire exercise and progress has been faster since then. And to keep "touch" from getting boring or predictable for him, I've been interspersing other cues as the reward, and occasionally rewarding only with food.
This concept of reinforcing a behavior with a cue is mind-boggling, and the idea that a cue with a long reinforcement history could be even more reinforcing than a "primary reinforcer" even more so. I'm not totally sure why it works or how it works. But I have now seen it for myself, so apparently it does work.
I don't really have any more solid plans for training than I did last week, but I sure have a lot of new ideas to think about!