Like John Barrer I have grave reservations about any grading scheme that
normalizes a class distribution to some arbitrary mean whether it be an A,
B, C, D, or F (although I doubt that anyone's ever tried the last couple)
regardless of performance.
If that grade is an A or a B, students quickly realize that everyone's
failure will become everyone's success! Grade inflation is unavoidable.
On the other hand, if that grade is a C or less we start seeing the
deleterious effects of competition to which Mike Monce refers.
Furthermore, in an environment where students have learned that B's are
the expected outcome of "average" (read "little") effort, encountering a
class which they perceive as difficult AND "harshly curved" will cause
many simply to give up.
Accordingly I too use an absolute grading scheme that allows me to assure
students that any and all of them CAN get A's and that cooperation and
productive work with their fellow students is the most likely route to
high grades. In addition, however, I have adopted additional policies
which I find to work quite well:
1) I give two midterms and a final. Each student's overall exam score is
the highest possible result of combining the individual scores subject to
the following constraints: The weights must add up to one, no weight may
be negative, no midterm may have a weight larger than 40%, the final must
have a weight between 40% and 70%. This allows me to accommodate almost
any combination of "bad days", absences, improvement bonuses, etc. I can
throw out a midterm if that is advantageous, heavily weight the final exam
if a student has improved, and so on.
2) All homework, daily reading memos, quizzes, class participation
scores, etc. go into an effort score between 0 and 4.
3) The final grade is based "purely" on the exam score using a scale that
is determined "purely" by the effort score. For example, with an effort
score of zero, students must achieve an exam score above 85% to receive an
A, 58% for a C, and 40% for an F. (Of course, these figures reflect my
own judgment based on my own exams and 25 years of teaching about what
constitutes various levels of achievement; they could and should vary for
others.) With an effort score of "2" (pretty easily obtained with a
little discipline), the A break point is reduced by just 3% to 82%, but
the C break by about 12% to 46% and the F break by 15% to 25%. With an
effort score of "4" (the maximum possible), the A break point is reduced
to 75%, the C break to 36% (!!), and the F break to 10% (!!!!!). (I
shouldn't need to tell you that I get *very* few students in a position to
take advantage of the last couple of breaks!)
Students like this scheme a lot because they see clearly that I am trying
to give them every opportunity to succeed. They see that there will be no
substitute for a high level of achievement on exams if they are looking
for an A but they also see that I am offering them a *very* buoyant and
readily obtained life preserver if they are worried about passing.
Am I disappointed that my average grade is still about a C+? You bet.
But I don't get *any* students coming in and arguing that my grade policy
is at fault.