Re: multi-step reasoning

[Brian Whatcott <betwys@DIRECTVINTERNET.COM>]

At 10:39 PM 8/20/02, you wrote:
> One place where students are called on to think beyond a simple relationship
> is with the ideal gas law
>
> PV = nRt
>
> I don't have my sources available but I was reading recently how nearly all
> students - including some graduate students in chemistry - faced with a
> question like "what will happen if V is doubled?" will either ignore one of
> the three variables, or apply them one step at a time in a sequential
> reaoning process, usually imagining a two-step process over time.
>
> What is going on is that they are trying to arrive at an answer
> algorithmically, when the algorithms won't give them a meaningful answer.
> What is needed is to have the students learn to habitually create models of
> situations, and consider carefully what all the constraints are on their
> models, before trying to crank out an answer.
>
> Students can learn this habit but they won't as a rule come up with it
> themselves.  Students want the easy way and that ain't it! But once they
> learn it they will find it is not just a more powerful way, it's also more
> satisfying.
>
> 8-)
>
> Chris Horton


Always wanting to be a necessary adjunct, even antidote, to the physicist
and teacher's world view of students, I note that if students want the easy
way with the ideal gas law, then no less did Newton, who similarly came
to grief in considering the pressure/temperature effects of sound, did
he not?


Brian Whatcott
  Altus OK                      Eureka!