Quoting Herman Rubin:
<< To make things more objective, multiple choice exams have
become at least a major source of "information". These
almost must be trivial pursuit; a good problem requires
at least 15 minutes of available time, and should not be
graded by the answer, but by the way it is approached and
treated. Even breaking it down to its parts loses so much
that the important parts cannot be tested. >> ,
Robert C. Knodt <[EMAIL PROTECTED]> wrote (edited for spelling &c.):
>It is difficult to disagree with the first part of this statement
>but I have a problem with the next part.
>Decision making is extremely important in the world today.
And when was it not?
>If there is work leading up to the decision that must be made
>and that work involves some error on the part of the decision maker
>the final answer may result in many things which are not reversible.
Whether error exists or not, there will be "things which are not
reversible". That's a consequence of the second law of thermodynamics.
As for error, "to err is human". Of course there will be error(s).
How do you propose to avoid them? (I want to watch!)
>Examples: Deciding to close a plant; not produce a product;
>send men into battle; select a dose of medicine; sell stock.
>All involve a decision.
Yep. And all such decisions are made with some error. If the folks
involved are lucky, the error(s) will not be fatal. Not everyone is
lucky.
>I don't see why we would give a student partial credit for doing a
>problem that results in a wrong decision.
Precisely so that s/he can learn to RECOGNIZE a wrong decision, and
perhaps even the error(s) that led thereto, when s/he sees one.
If you don't discriminate between what they do wrong and what they
do right (to oversimplify immensely), how do you expect them to learn
how to do it right the first time?
>The most important thing is the answer, not how it is approached.
Ah. You would, then, give full credit to the student who got "the
right answer" by copying a colleague's paper? Or by casting straws
and invoking the I Ching? Sorry: I heartily disagree. Both are
important, and for learning to cope with the world, how to approach
a problem is in general more important to learn (sometimes MUCH more
important) than the answer. (After all, the answer is only "right"
(if it IS right) for that problem. The next problem like this one
will almost certainly have a different "right" answer.
[Again, I oversimplify. Most of the time there is no such thing as
"the right answer": there are only wrong answers, which differ in
the degree and what one might call the direction of wrongness. For
some of these, the degree or wrongness may be small enough that one
would be willing to call them "right" answers; but there NEVER is,
for any interesting problem, only one ("the") right answer.]
>The approach may be correct but the calculations may be faulty.
Then the student needs to KNOW that it is the calculations, not the
approach, that is faulty.
[Aside: When I was an undergraduate, I nearly flunked a course in
German. After the midterm exam in second term, my instructors made
a point of letting me know I was in difficulty. They did not, however,
identify the area of difficulty. _I_ thought I had a decent handle on
the grammar, but was not fluent enough in oral discourse and/or proper
pronunciation; so I concentrated on the latter during the rest of the
term. AFTER the final exam, with a course grade of 55 (technically
failing, but possible to overcome it with a make-up exam the next
September) they told me that the mid-term mark was as high as it was
because I was (in their view) unusually fluent in the oral language,
but was not doing at all well with grammar etc. Whether focussing on
the grammar would have changed the semester outcome I do not, of course,
know -- as Robert so correctly points out, one cannot go back and do it
over again. But it has made me sensitive to the kinds of distinction
that are useful to make, especially when they are not being made.
(FWIW, I passed the September exam and the final course mark was, if
I remember correctly, 70. But that's another story.)]
>Fire 32 men and close the plant. The decision is made.
>You can't come back three months later and say "Woops, I made
>an addition mistake. Let's reopen the plant."
>It is WRONG to give partial credit when it leads to the wrong answer ...
"THE" wrong answer? Is there really only one???
> ... which results in a bad decision that may affect people's lives.
So if you're in the business of training students, who more or less
by definition haven't learned how to do this stuff yet, WHY are you
giving them problems whose consequences "may affect people's lives"?
>Would you like to hire an individuals who attained a grade of 80
>knowing that he/she made a number of mistakes in decision making
>but was given partial credit?
Do I have a choice? If his/her grade is only 80, evidently s/he has
made a number of errors of SOME kind, and nonetheless did not flunk
the course (which would seem to be the logical consequence of the point
of view Robert appears to be espousing here).
>Isn't the purpose of education to produce students who make good
>decisions?
Indeed. And how can one POSSIBLY do that, except by letting them make
decisions (a) in circumstances where the consequences of bad decisions
are at least unlikely to be fatal; (b) that may turn out to be wrong
decisions, so they can learn to diagnose their own errors; (c) for
which you are prepared to diagnose what they did wrong AND what they did
right -- and by "diagnosis" I do NOT mean assigning a mark of zero for
all work that is not 100% "correct" (according to the instructor's
understanding -- which may itself be faulty)?
Some time ago I began to tell students, early in any course:
Notwithstanding the assertion that only two things in life are certain,
there are in fact four certainties that you can count on:
1. You will die.
2. You will pay taxes.
3. You will be wrong.
4. You will not know when.
In a certain sense, that says it all... -- Don.
-----------------------------------------------------------------------
Donald F. Burrill [EMAIL PROTECTED]
56 Sebbins Pond Drive, Bedford, NH 03110 (603) 626-0816
.
.
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