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Re: Extra Credit (was Where Have All the Boys Gone?)



While Thomas O'Neil's questions below are difficult, I think there are some
things that should be clear from the Physics Educational Research programs.
Courses built entirely around individual problem solving (especially back of
chapter problems) and 'cook-book' labs are not going to serve either the
students or the Physics profession very well. In my mind we must include a
major dose of 'Conceptual Physics' and the assessment thereof within all our
introductory courses. My method of doing this is to have weekly quizzes on
the concepts, weekly problem solving homework (that IS graded) worked in
groups, and a couple of problem solving tests (where some limited reference
material can be used) that have very liberal (to no) time constraints. This
last I accomplish (this is College level) by letting students take the test
during any two hour block on the given day (8-AM to 8-PM) and then I don't
force papers in if a student really needs more time. I then give them off a
day to compensate for the test. [I write an hour test and then tell them
they have 2-hours (or more) to work it--therefore I need only compensate for
the 1 hour the test is 'supposed' to take.] The conceptual quizzes account
for 25% of the grade, their lab work (which is an eclectic mix of lab
styles) another 25%, the 'group work' homework (the group turns in one
solution set) as another 25%, and finally the tests count the last 25%. I
don't know if this mix is the best, but it seems to work fairly well for me.
The quiz part will clearly identify those who can 'do the math' but don't
really understand the physics. I will say that the homework problem sets
are not just back of the chapter problems. I do use some of those (usually
the mid-level problems) but also include some 'real-world' problems along
the lines of what the Heller's suggest. I of course offer help (but not
full solutions) to the groups when they need it on homework and labs. The
main point here is that I think we fool ourselves if we think that
end-of-chapter problem solving can assess conceptual understanding. What
good is it if a student can score 90% on problems but under 50% on the FCI
(or similar assessment tools)?

To be sure, recent survey's of working physicists rate 'Real-World' problem
solving skills as the number one required skill and group interaction skills
are also way up there. Writing and speaking skills are also ranked well
above 'Physics Knowledge', but it is also quite logical that one cannot
really succeed without the knowledge component. However, solving
back-of-chapter problems doesn't make the list at all! ;-)

Rick

**************************************************
Richard W. Tarara
Associate Professor of Physics
Department of Chemistry & Physics
Saint Mary's College
Notre Dame, IN 46556
219-284-4664
rtarara@saintmarys.edu

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www.saintmarys.edu/~rtarara

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----- Original Message -----
From: "Thomas O'Neill" <o'neill@CSVRGS.K12.VA.US>

So I will ask the question that has always bothered me: Once a
physicist/chemist/engineer/scientist leaves school, when will he/she/it
ever take another test? Because the issue of extra credit and testing
assumes that testing is a better method of evaluating student mastery of
the material. Tests revolve around solving known problems with limited
resources in a fixed time. Most professionals that I am aware of, do
not approach problem-solving with those skills. Indeed, the first step
to successful professional problem-solving (What has been done on this
problem by others?) is called cheating in a test context.

If a person was actually good at test-taking, how does that
translate into useful professional skills? I certainly believe that the
mastery of the material must be demonstrated by the student, but is a
two-hour exam the best way to do it? Put it another way, does doing
well on the Physics AP or Physics SAT II correlate with success in a
scientific or engineering career? Should colleges (particularly the
sciences) move to some other method of evaluation? Because I figure
that I am emphasizing testing because my students will encounter it at
college.

Note that I do not have answers to these questions and I do use
timed tests in my class.


THO