Hi all-
John Clement, after an apparent hasty reading, writes, in part:
I disagree violently with the idea of the "magic X". This sets up the
student for failure later by making X and Y the only variables. Variables
should be introduced first as words such as money or time... then later
shorthand single letters could be used. The widespread almost exclusive
usage of X, Y sets up students to not use other variables when they get to
chem. and physics. Just inserting some equations involving t or V or
whatever doesn't help later. The fact that these variables are introduced,
but students are never asked to attach any meaning to them, just makes them
random gobbledygook. Learning some elementary computer programming can be
helpful here if it is taught in such a way as to promote metacognition.
_____________________________________
John doesn't really argue against my advocacy of "magic X",
because I am not advocating sticking symbols into equations. I am
advocating having students solve problems by formulating equations using
variables - quite a different matter. Most college students that I have
encountered don't do this vey well. The process starts with - as I said -
having students decide where they are going with the problem, what it is
that they are solving for, and saying "let X (or u, or \phi) stand
for...." My 65 year old high school algebra text has problems where
students were actually required to do this.
Setting up the equations is the hardest part of thinking, as
Slater and Frank noted in their mid-thirties textbook (the one that
Feynman presumably used as an undergrad).
Regards,
Jack
--
"Trust me. I have a lot of experience at this."
General Custer's unremembered message to his men,
just before leading them into the Little Big Horn Valley