Re: [Phys-l] Should equation solving be done with calculators and robots or by hand?

[Rick Tarara <rtarara@saintmarys.edu>]

----- Original Message ----- 
From: "Steve Highland" <shighlan@uslink.net>
To: "Forum for Physics Educators" <phys-l@carnot.physics.buffalo.edu>
Sent: Wednesday, February 27, 2008 10:57 PM
Subject: Re: [Phys-l] Should equation solving be done with calculators and 
robots or by hand?


> I think my earlier posts may have given the impression that I want to go 
> too
> far in reducing algebra manipulations in physics problem solving.  My goal
> is to make better use of robots to take care of 'chore' sorts of tasks 
> that
> steal attention and time that I think could be better devoted to 
> expressing
> physical reasoning in words and interpreting the *meaning* of answers.
>
> Piles of algebra just aren't what I'm looking for in solutions to physics
> problems.  That seems to be what a lot of students crank out, though.  I
> want language instead.
The suggestion that increasing the use of computer aids in problem solving 
might be beneficial to student's understanding suggests to me that too many 
problems are being assigned.  I limit assignments to about 10 problems per 
chapter and all of those tend to be 2nd (mid) level (books vary in how such 
is indicated) problems which tend to avoid the 'plug & chug' style of 1st 
(low) level problems and the complex math manipulations of 3rd (high) level 
problems.  I supplement with Heller-style 'real-world' problems.  This 
number usually can cover the 'different' problem types in a given chapter.

The algebraic manipulations ARE part of the learning process, the thought 
process, the skill learning.  They sharpen the student's logic.  OTOH, I 
have no problem with students getting numerical answers for a quadratic 
equation from a higher level calculator function or using the matrix solving 
capabilities of their calculators to solve something like Kirchoff equations 
since students would have to get the 'physics' correct to get to that point. 
In my Calculus level course, I often (always on tests) accept the integral 
with appropriate limits as the solution.  I know the students can look up 
the integral and (by that point in the course) do any algebraic 
manipulations.  Setting up the integral for an appropriate solution contains 
all the physics.

I do like the idea of getting _some_ programming into the course--it can 
really help basic understanding.  I've lost a semester out of our 
Chem-majors sequence and consequently have had to drop a programming 
exercise (retain spread-sheet exercises), but when I was doing this (having 
them program a 2-d electric charge interaction--with animated charges), I 
could teach the class the programming needed by using TrueBasic which has 
very intuitive commands and very algebra like structures.  I would spend no 
more than half a class on the programming and then give the programming 
project as a one-week assignment.

Using the technology is much more 'job' related than it is basic knowledge 
and skill related.  Too much technology and too little knowledge can be a 
dangerous mix.  ;-(

Rick

***************************
Richard W. Tarara
Professor of Physics
Saint Mary's College
Notre Dame, IN
rtarara@saintmarys.edu
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