大头针上的天使
Alexander Calandra
亚历山大·卡兰德拉
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.
前些时候,我接到一个同事的电话,问我可否就一道考题的打分作一下仲裁。他打算给一个学生的物理考题答案打零分,而那位学生却声称,如果现行的教育制度不是专门要和学生作对,他就该得满分,也一定会得到满分。师生俩同意把这事交给一个不带偏见的仲裁人来处理,于是我就被选中了。
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 (气压表)."
我来到同事的办公室,读了考题:“证明如何借助气压表测定出大楼的高度。”
The student had answered: "Take the 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."
学生答道:“把气压表带至楼顶,在气压表上系一根长绳,将表下垂至地面,然后将其收回,量一下绳子的长度。绳子的长度即为大楼的高度。”
I pointed out that the student really had a strong case (强有力的论据) for full credit(满分),since he had answered the question completely and correctly. On the other hand, if full credit were given, it could well contribute to a high grade for the student in his physics course. A high grade is supposed to certify (证明)competence in physics, but the answer did not confirm (证实) 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.
我指出,该生确实有充分的理由得满分,因为他圆满而正确地回答了这道考题。话又得说回来,要是给满分的话,这位学生的物理课成绩就能得高分。高分应证明学生在物理学方面的能力,而这一解答并不能证实这一点。于是我建议再给该生一次机会,让他再解答一遍。我同事答应了,这我不觉得奇怪,但我没料到那学生居然也答应了。
I gave the student six minutes to answer the question, with the warning that his 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 (匆匆写出)his answer which read:
我给这学生6分钟时间答题,并提醒他答案必须显示出物理学方面的某些知识。5分钟过去了,他仍一字未著,我问他是不是想放弃,他说不。对这问题他有好几个答案;他只是在考虑选取最佳的一种。我抱歉打搅了他,请他接着思考。在最后一分钟,他匆匆写出了如下答案:
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 (跑表).Then, using the formula S=(1/2)at^2, calculate the height of the building.
“将气压表带上楼顶,在顶沿俯身抛下气压表,同时用秒表测定气压表的下落时间。随后用S=(1/2)at^2的公式,即可求出大楼的高度。”