Some time ago I received a call from a colleague, who asked if I
would be the referee on the grading of an examination question.

He
was about to give a student a zero for his answer to a physics
question, while the student claimed he should receive a perfect
score and would if the system were not set up against the student.

The instructor and the student agreed to an impartial arbiter, and I
was selected.

I went to my colleague's office and read the
examination question: "Show how it is possible to determine the
height of a tall building with the aid of a barometer."

The student had answered: "Take the barometer to the top of the
building, attach a long rope to it, lower it to the street, and then bring
it up, measuring the length of the rope. The length of the rope is the
height of the building."

I pointed out that the student really had a strong case for full credit
since he had really answered the question completely and correctly.

On the other hand, if full credit were given, it could well contribute to
a high grade in his physics course. A high grade is supposed to
certify competence in physics, but the answer did not confirm this.

I suggested that the student have another try at answering the
question. I was not surprised that my colleague agreed, but I was
surprised when the student did.

I gave the student six minutes to answer the question with the
warning that the answer should show some knowledge of physics. At
the end of five minutes, he had not written anything. I asked if he
wished to give up, but he said no. He had many answers to this
problem; he was just thinking of the best one. I excused myself for
interrupting him and asked him to please go on.

In the next minute, he dashed off his answer which read:
"Take the barometer to the top of the building and lean over the edge
of the roof. Drop the barometer, timing its fall with a stopwatch.
Then, using the formula x=3D0.5*a*t^2, calculate the height of the
building."

At this point, I asked my colleague if he would give up. He
conceded, and gave the student almost full credit. In leaving my
colleague's office, I recalled that the student had said that he had
other answers to the problem, so I asked him what they were.

"Well," said the student. "there are many ways of getting the height
of a tall building with the aid of a barometer. For example, you could
take the barometer out on a sunny day and measure the height of
the barometer, the length of its shadow, and the length of the
shadow of the building, and by the use of simple proportion,
determine the height of the building."

"Fine," I said, "and others?"

"Yes," said the student." There is a very basic measurement
method you will like. In this method, you take the barometer and
begin to walk up the stairs. As you climb the stairs, you mark off the
length of the barometer along the wall. You then count the number
of marks, and this will give you the height of the building in
barometer units.

"A very direct method."

"Of course. If you want a more sophisticated method, you can tie the
barometer to the end of a string, swing it as a pendulum, and
determine the value of g at the street level and at the top of the
building. From the difference between the two values of g, the
height of the building, in principle, can be calculated."

"On this same tack, you could take the barometer to the top of the
building, attach a long rope to it, lower it to just above the street, and
then swing it as a pendulum. You could then calculate the height of
the building by the period of the precession".

"Finally," he concluded, "there are many other ways of solving the
problem. Probably the best," he said, "is to take the barometer to the
basement and knock on the superintendent's door. When the
superintendent answers, you speak to him as follows: 'Mr.
Superintendent, here is a fine barometer. If you will tell me the
height of the building, I will give you this barometer.'"

At this point, I asked the student if he really did know the
conventional answer to this question. He admitted that he did, but
said that he was fed up with high school and college instructors
trying to "teach him to think".

This makes me wonder if this explains politics? Maybe they are
smarter than they look . . . They know the simple, correct answer,
(Yes or No) but they just enjoy confusing us with hour long
monologues with an amibigious answer, because they want to make
us think.