In time I will argue--successfully, I hope--that the no doubt confusing philosophizing going on in my previous post on this topic was neither a hypocritical misapplication of good principles of information organization nor a faithful application of bad principles.For now, though, the confusing post remains, and I shall do my best in this one and the next few to try to make my thoughts clearer while expanding on them a bit from what I hope to be a firmer foundation.
Because of (among other things) education's enormous social and institutional complexity, even reasonable, mainstream discussions within mathematics education tend to suffer from a kind of bongo-bongoism, "the venerable but ultimately sterile anthropological practice of countering every generalization with an exception located somewhere at some time":
When a generalization is tentatively advanced, it is rejected out of court by any fieldworkers who can say: 'This is all very well, but it doesn't apply to the Bongo-Bongo.'*This is not so much a bug as it is a feature of the discourse among educators who directly and daily influence the learning of students. After all, these are people who traffic in exceptions rather than rules--for whom bongo-bongoism is a necessary, valuable, critical orientation toward "outside" ideas (from research, standards, professional development gurus, and textbooks) that often miss the trees for the forest (or, rather, the students for the statistics).
Yet it is one thing to be naturally suspicious of generalization and quite another to treat it as a thought crime. On this view, Eratosthenes's investigations concerning the circumference of the Earth should never have begun given that they were based on wild assumptions about the shape of the planet, the direction of the Sun's rays, and the locations of cities in Egypt. Better to wait for a 25,000-mile-long tape measure. Darwin's belief-shattering ideas, too, are ridiculous in this light. Were you there? is a question indoctrinated children are taught to ask of those who present the evidence for the theory of evolution by natural selection. This is much worse than missing the forest for the trees. It is missing the forest for the missing trees.
Mathematics education desperately needs a good generalization--one that, at the very least, can keep its denizens somewhere between a healthy bongo-bongoism and a destructive solipsism.

