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Re: FAST: exemplary middle school science



I would like to thank Hugh Haskell for the review of FAST.

I have not been involved with FAST in any way, but I have been involved in
many lab exercises with current middle-school and high-school science
teachers, and have been heavily involved with pre-service teachers because
my college has a fairly large education department.

Hugh hit upon something that is epidemic... poorly designed experiments that
don't work or give results that are ambiguous. Time and again I have seen
teachers or teachers-of-teachers demonstrate a "wonderful" experiment that
is supposed to demonstrate something, but in reality it doesn't work, or it
demonstrates something else, or it gives results no one can interpret.
Sometimes the instructor doesn't even realize things don't make sense.
Often the instructor realizes things don't make sense and passes it off as
"well we didn't really do this with good enough equipment, but you get the
general idea." No... I don't get the general idea. If the experiment
didn't yield something pretty close to the expected result and/or didn't
measure the number it was supposed to measure, then what's the point?
Occasionally that question has been answered with "well at least we got the
students into the lab and doing real science." Geesh; might as well just
let them into the lab to play with the equipment; they might learn more. I
don't think they are doing real science unless (1) it gives the desired
result, or (2) it does not give the desired result but students and teacher
work together to figure out why.

The point is, if we're going to do experiments, they had better work
reasonably well most of the time. Yes, I know students need to learn that
not every experiment works perfectly; and students need to learn about
statistics and uncertainty; and they need to know our theories are often
based upon experiments with large uncertainties. They also need to struggle
with figuring out what went wrong. But students dare not conclude
experiments never work or experiments usually give non-interpretable
results.

You've probably heard the joke: if it wiggles and squirms it's biology, if
it fizzes and stinks it's chemistry, if it just plain doesn't work it's
physics. Yet this is usually what happens when we try to do table-top
physics experiments with stuff we buy at a grocery store or hardware store
and we don't take considerable time to work out the kinks.

I spend many hours working out the kinks so roughly 75% of my experiments
work very well, yielding errors typically less than 5%. In these cases I
try to show students my earlier results and talk about the things already
done by me or previous classes to get the experiment to the point it works
well now. But I also assign a few experiments where the bugs have not been
worked out. Some of these yield 10% error and some yield 30% error or even
worse. I invite students to suggest ways to improve the experiment.
Sometimes I still don't know myself what is going wrong.

However, I don't want to assign more that one lab a semester with terrible
results. If I am doing an experiment each week for a semester (roughly 14
lab sessions), I might like one to work poorly, two or three to come out
mediocre, and the rest to come out quite nicely. I want my students to know
it doesn't always work well, and to think about why not, but I certainly
don't want them to say "if it just plain doesn't work it's physics."

Granted, I am working with college students, but I see no reason this
approach cannot be taken in middle school. I encourage our middle-school
and high-school pre-teachers to work very hard at stealing, borrowing,
designing experiments that work. Poorly-conceived experiments do more harm
than good. I am afraid this means we need to spend more time and money on
equipment and working out the kinks than many "new educational programs" are
willing to spend.

I also agree with Hugh about the absence of middle-school teachers in lab
curriculum design. When I am at my best (with respect to middle school
science) I am trying to help a middle school teacher figure out how to
perform a new experiment or improve an old one. I have lot's of ideas and
technical skills, but they have lots of experience with this age group and
with the State mandated curriculum. When I make suggestions I often hear
things like... okay, now you need to cut the cost by a factor of 10...
remember, there are 25 kids in this class, not 10... remember, our lab
period lasts only 50 minutes... I only have one computer per 6 students...
but seventh graders haven't had any trig yet...

You get the picture. Meaningful, appropriate for the age level,
inexpensive, short-time duration... experiments that work... are very
difficult to design.

Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817