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Re: Projectile Motion



I've done similarly -- I tell the students that I scale the test. Thereby, if
they nearly all do poorly, i.e. get </= 60%, there still will be A's, B's,
C's, etc. I do this by plotting the scores (student number bins, ordinate; %
or absolute, abscissa). I'm continually surprised how often the scores are
bunched, so the dividing line between the grades is between the bunches.
Also, as expected for classes > /= 20 the bunches are ~ Gaussian. This method,
also, is less arbitrary than giving only e.g. two A's, seven B's, ten, C's, and
three D's and F's than when it's obvious there should be five A's, etc.

bc who thinks RT's method of compressing is "cute" and will try it next time.

Rick Tarara wrote:



cut

What you can do
with those kind of grades is use a 'square-root curve'. Take the square
root of their score times the square root of a perfect score. For tests out
of 100 then a 64 becomes an 80, an 81 becomes 90, etc. If raises and
compresses the scores but still maintains a differential between the high
performers and the low.

Rick

----- Original Message -----
From: "Tina Fanetti" <FanettT@WITCC.COM>
To: <PHYS-L@lists.nau.edu>
Sent: Tuesday, September 24, 2002 7:54 AM
Subject: Re: Projectile Motion

Not having taken all sorts of fancy education courses or statistics....

Does it mean anything if the grades are clustered together, say around 60?

Tina

Tina Fanetti
Physics Instructor
Western Iowa Technical Community College
4647 Stone Ave
Sioux City IA 51102
712-274-8733 ext 1429