LOL. That's great. I think that's one cool thing about homeschooling/afterschooling (and perhaps about CBT, depending on the program): you can do constant stealth assessment, and really deemphasize the summative stuff. Someone in another thread on this board mentioned that they were "co-learning" with their kid, and in doing so, realized that they gained a superficial understanding of the material -- the very common practice of knowing enough to pass the test -- while her ds was learning in a completely different, richer way.
Anyway, sounds like an interesting book, Inky. Going beyond the book for a moment to think about research on education in general, it just occurred to me that I want to do things in an evidence-based way, but I'm coming to realize that there just may not be any good evidence for a lot of the forks in the road we will be facing with dd.