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So this grade is based purely on evaluating their technique
only with the assumption that if their technique is proper
they will achieve a result to within 1% of the supplier's
value.
I have several questions about this, based on my experience in
spending a year trying to undo some of the habits these
students come into physics with.
First, do you have the students evaluate why the established
technique is capable of yielding a 1% discrepancy?
If they get greater than a 1% discrepancy, are they then made
to determine the source(s) of the increased value?
What are the limits of the supplier's value?
I still need to be convinced that such a grading technique is
not a pedagogical error.
The students arrive in my physics classes convinced in the
"rightness" of any value given in the book. They are obsessed
with the "percent error". They are shocked to learn that if
they measure a value for g to be 9 +-1 m/s^2 that their value
is actually in agreement with the "accepted" value, as long as
their uncertainty is an accurate calculation of the limits of
their measuring system.
They never seem, especially at the beginning, to be able to
question the accuracy of their equipment, or the experimental
technique being used. All "percent error" is attributable to
"human error".
Is the purpose of the course simply to teach established
techniques and methods which are regarded as simply skills a
chemist needs? Then, maybe, the grading is appropriate.
But you should be aware of the ideas this plants in the
student's mind as to how experimental work proceeds.