Tuesday, February 27, 2007

Interesting article

Read this a long time ago and recently rediscovered it on the net... If everyone were to be thinking students like the student in the story below, what an exciting class that would be! Don't you agree, fellow teachers and students?

Incidentally, those who enjoy the story will enjoy reading Richard Feynman, who is a "thinking man's physicist". Pick up any of the books about him in the school library -- you'll be enthralled.
(Books are: Surely You're Joking, Mr Feynman; What Do You Care What Other People Think?; Genius by James Gleick.... and a few others)

=)
Mr Koh

PS: After reading the article, post your responses to this question: "What is the conventional answer to the test question?" You'll only fully appreciate the alternative answers if you also know the conventional one...


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Angels on a Pin

A Modern Parable
by Alexander Calandra
Saturday Review, Dec 21, 1968.


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 submit this 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 a barometer to the top of the building, attach a long rope to it, lower the barometer 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 answered the question completely and correctly. On the other hand, if full credit was given, it could well contribute to a high grade for the student 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 that 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 that barometer, timing its fall with a stopwatch. Then using the formula S = ½at², calculate the height of the building.

At this point I asked my colleague if he would give up. He conceded, and I gave the student almost full credit.

In leaving my colleague's office, I recalled that the student had said he had many other answers to the problem, so I asked him what they were. "Oh yes," said the student. "There are a great many ways of getting the height of a tall building with a barometer. For example, you could take the barometer out on a sunny day and measure the height of the barometer and the length of its shadow, and the length of the shadow of the building and by the use of a simple proportion, determine the height of the building."

"Fine," I asked. "And the others?"

"Yes," said the student. "There is a very basic measurement method that 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 wa]l. 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 of the two values of `g' the height of the building can be calculated."

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 I have a fine barometer. If you tell me the height of this 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, said that he was fed up with high school and college instructors trying to teach him how to think, using the "scientific method," and to explore the deep inner logic of the subject in a pedantic way, as is often done in the new mathematics, rather than teaching him the structure of the subject. With this in mind, he decided to revive scholasticism as an academic lark to challenge the Sputnik-panicked classrooms of America.

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The article is by Alexander Calandra and appeared first in "The Saturday Review" (December 21, 1968, p 60). It is also in the collection "More Random Walks in Science" by
R.L.Weber, The Institute of Physics, 1982.

Calandra was born in 1911, started at Washington University (St. Louis) in 1950 as Associate Prof. of Physics. B.S. from Brooklin College and Ph.D. in statistics from New York Univ. Consultant, tv teacher and has been AIP regional counselor for Missouri.

4 comments:

Frank Chen said...

Some attribute this to Niels Bohr during one of his physics examinations.

I suppose the reason behind why students can't think so creatively is as they are far too well-trained to answer examination questions correctly and in the manner prescribed by UCLES instead of really thinking through the possibilities and intricacies involved in the questions.

The Americans are far more relaxed to think and appreciate the wonders of the sciences as they have varied modes of assessments for them (presentations, projects, etc...) instead of just one big examination at the end of 6 years of education.

I suspect you may not find this kind of thinking in RJ either, but more likely in schools like NUS High, where they don't have to take the A-levels and is thus freed from the "spectre" of examinations.

A sad situation, but with an assessment system like ours, inevitable.

~ Chen Shuang

rejuvenated said...

eh... how does the conventional method go? sorry ar. i IQ a bit low for STP.

-anne-

Drakonid_Hart said...

very surprised by the wide variety of answers provided by the student. Answers that i personally wouldnt have thought of.

I wonder if this is a result of us being so in tune with the school's and cambridge's marking scheme. Rather than taking chances with our all important results, we instead choose to take the well worn and 'normal' path when it comes to answering questions.

I feel that the grading criteria in singapore simply does not allow such liberties in our answers as many would feel that any risks taken would be too costly. Then again, it may not be our creativity in question, but our courage to challenge the norm.

-xiuyi

Teck said...

Hi Chen Shuang, Anne and Xiuyi,

I agree with you about exams stifling creativity and thinking...

Just look at SPA! Sigh... Practicals were much more fun and felt more like science practicals before SPA was implemented..

I dunno how much your uni lecturers much unteach for practicals when u get to uni...

SPA is a big reason why i would seriously consider not teaching anymore...