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Re: Concerned about grades

Greetings,
While teaching physics in high school in the 60's, I came across a study in The Physics Teacher that looked at why students were not taking physics. There were two main reasons. One was that previous science teachers had turned them off. The other was that physics teachers were too hard a grader. The first, I had no control over. The second I did.

So I looked at how I graded to see if I was too hard a grader. For four or five years of class data, I took the 6 6-weeks grades and made a "GPA" for each student. I then determined an average "GPA" for each class. Next, I went to each student folder and obtained their GPA for all classes taken prior to taking the physics class. I likewise found an average GPA for the class. The result.....

My physics class "GPA" was from 0.6 to 1.1 lower. Relative to the rest of the teachers in the school, I was too hard a grader. Why, I thought. I think it was because I was taught to use the bell curve. Yet, I did not have a school wide student body. I played around, adjusting my physics grades. Why, I don't remember, I changed my bell curve to the center being a 'B' rather than a 'C'. My class GPA then fell in line with the student's GPA.

To this day, I adjust my average grade to a 'B' for tests and quizzes. (Not for laboratory reports.) Three times since then I have rechecked to see how my GPA compared with their GPA before entering physics. Each time my physics grades were in line. My physics student enrollment hovers around 60% of each graduating class. It was 25% before making the adjustment.

Will it work for you? On analysis of your grading will answer this question.

Helping teachers who teach, motivating students who learn.
"Science is nothing more than learning how to communicate with nature in such a manner that it will talk back."

Dick Heckathorn 14665 Pawnee Trail Middleburg Hts, OH 44130-6635 440-826-0834
Physics Teacher Cuyahoga Valley Christian Academy 4687 Wyoga Lake Road Cuyahoga Falls, OH 44224 330-929-0575 VM 120


-----Original Message-----
From: William J. Larson [SMTP:bill_larson@CSI.COM]
Sent: Thursday, March 16, 2000 1:33 AM
To: PHYS-L@lists.nau.edu
Subject: Re: Concerned about grades

My physics teachers (U of Minn.) tried to get the test means to be 50%
and expected scores all the way from near zero to 100. Their thinking
was that that spread the scores out for maximal discrimination between
performance. I remember one test being thrown out because the mean
was too high (maybe 75% - I forget.) This was 20 years ago.

Cheers,
Bill Larson
Geneva, Switzerland
----- Original Message -----
From: Lemmerhirt, Fred <FLemmerhirt@MAIL.WCC.CC.IL.US>
To: <PHYS-L@lists.nau.edu>
Sent: 2000 March 16 4:05 AM
Subject: Concerned about grades


Long ago (1964-69), as an undergraduate student and graduate teaching
assistant, I was accustomed to exam averages and corresponding grading
scales in physics courses being rather low. So I was not surprised that
during my first few years of teaching on my own I settled on a grading
scale
with "cutoffs" that were somewhat lower than students were used to in some
of their other courses. My explanation to students has always been that
there is very little "padding" on my exams, and that someone who might get
30% or so on a multiple-choice exam in another course without "opening the
book" would probably get something closer to zero on a physics exam.

I get to know my students' level of understanding and achievement fairly
well, independent of exams, and I usually feel that the grading scale I
use
assigns appropriate grades to most students. So, working in relative
isolation, I have been generally satisfied with the grades I submit. But
now
that I am able to look at many course syllabi on physics department web
pages at a wide variety of colleges and universities, I find that the
great
majority of published grading scales use cutoffs substantially above those
of my own scale. (Specifically, my C/D dividing line is usually around
55%,
while I find the D/F line is most commonly 60%.)

In working with community college transfer students, one of my goals is
that
their physics experience, including the way they are evaluated, should be
roughly equivalent to what they would have encountered at the schools to
which they transfer. So I am wondering if any of you have philosophies on
this aspect of grading that you are willing to share. How concerned
should
I be about this?

______________________________________
Fred Lemmerhirt
Waubonsee Community College
Sugar Grove, Illinois
flemmerhirt@mail.wcc.cc.il.us <mailto:flemmerhirt@mail.wcc.cc.il.us>
http://chat.wcc.cc.il.us/~flemmerh/physics.html
<http://chat.wcc.cc.il.us/~flemmerh/physics.html>