mtt2k

Posted on August 16, 2012

I toyed with making oh, a dozen more critiques of Khan Academy videos… starting with addition… but I think I’ll just mention a few pedagogical issues I have (a.k.a. “trashing” to some).

I remember loving spelling lessons.   THere were always a few exceptions in there and I’d analyze them to death and figure out a reason, whether fact or fiction — but I’d look for a real pattern, not just a mnemonic. Those -sion words?   So many come from base words with a softer ending — -ide or -ise instead of -ite.   Collide, revise, provide, explode…

When I started teaching, I began thinking that teaching exceptions as “proof of the rule” was a good idea; that others would find them fascinating, too.

I soon realized that was a complete bust.

Once you’ve mastered something, then you revel in the exceptions.   If you try to learn the exceptions with the foundation, then you stay confused and you join those folks who think “we shouldn’t teach spelling because there are exceptions to everything.”

I see this happening in Khan Academy lessons regularly.  WIth essentially *every* lesson I saw, he introduced the procedure and then leapt to sources of common misconceptions, without resolving them.

If you’ve already mastered the math, that’s fun.

Guess what?   Most students have not already mastered math. Remember, his approach is supposed to be *better* than our “failed” ways… except they’ll only work for the folks who would succeed anyway.

I don’t have that perseveration thing that Sal Khan has — so I can resist the urge to describe, in detail, how he has done this in every video I saw. (Really. Resisting. Resisting ;))  I *really* want to a: actually get a nice visual  animation of how to get from a number line to algebra (3 < x < 9) to interval notation, and b: figure out how to script increasing scores, and c: start figuring out the variables and equations and loops and if:then thingies for interactive lessons in exponents.

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