<html><head><style type="text/css"></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">The important thing about what the computer does in this case -- repeated incremental additions -- is that the children can and do carry it out themselves. They do not need to understand in any way how the computer actually does this. This is a critical part of how understanding is done here. In fact, I've written and lectured elsewhere about the excellent approach to using incremental addition (by hand) by the first grade teacher Julia Nishijima. And, not to be provocative, but in any case, even if the children didn't do it before they use the computer, I don't think too many people would conclude that hiding simple arithmetic is in the same category as hiding differential equations. One is not mysterious, and the other one is. And I was not talking about "a level of description" but about what human representation systems can and can't do with respect to "what's out there?". Best wishes, Alan <div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><hr size="1">From: Joshua N Pritikin <jpritikin@pobox.com> To: Alan Kay <alan.nemo@yahoo.com> Cc: Bill Kerr <billkerr@gmail.com>; iaep SugarLabs <iaep@lists.sugarlabs.org> Sent: Saturday, August 22, 2009 8:20:01 PM Subject: Re: [IAEP] Physics - Lesson plans ideas? On Sat, Aug 22, 2009 at 04:49:53PM -0700, Alan Kay wrote: > Four months earlier they did some play with this with the cars on > their screen and are able to see that this should be the same model, > but vertically not horizontally. They write a script with the two > "increase by"s and then find a way to see if their simulated ball > moves the same way as the dropped ball on the video. And it does. > > This was real science in every particular. It's wonderful to watch > them do it. > > Now they have a "pretty good" mathematical model of what they could > observe in "what's out there?". (Or as Newton liked to say "pretty > nearly".) The model isn't the same as what's out there. It doesn't > depict "what's out there?". To me, this evidence suggests that the children are culturally prepared to do science at this level of description. Discovering a basic model of gravity is within their proximal zone of development. However, I don't think this suggests anything intrinsic about the level of description kids are working with. That is: > Everything in a language describes something in a "story space". That > is all language can do. There is nothing instrinsically about the form > of any story that makes it relate to "what's out there?" in any > necessary way. Math tries to be consistent and to chain reasoning > together but this is not enough to reveal anything about the universe. > It's still a story. To repeat, it is the child's cultural training that makes this level of description special at this age, not anything intrinsically special about the level of description. For example, thinking about acceleration in terms of repeated addition is still quite high level. To really understand how this works, you need to understand binary arthimetic and how this is implemented at the hardware level. Or to go even more low level, you need to understand the physical properties of transisters to understand the opereation of logic gates. A priori, there is no reason to pick one level of description or another except that we want to pick a level of description that happens to be in the kid's zone of proximal development. The examples I just cited are lower level, but I don't see any reason not to pick higher level examples, like the Physics activity. I agree the Physics activity hides the math involved in solving differential equations, but Etoys similar hides the low level assembly language that is actually how CPU accomplish computation. So to me, it all comes down to: > Science is the process of trying to put what we can investigate and > think about "what's out there" in as close a relation as possible with > what we can represent in symbols. In practise this is a kind of > coevolution. And I don't see why you don't do that with the Physics activity. For example, recently somebody posted a Physics screenshot that showed how to simulate an earthquake. Now do earthquakes really work like that? No, of course not, but it is a reasonable model that can lead to predictions and actual experiments. </div></div></div> </body></html>