Barometer Question - Calandra's Account

Calandra's Account

A colleague of Calandra asked the barometer question to a student, expecting the correct answer: "the height of the building can be estimated in proportion to the difference between the barometer readings at the bottom and at the top of the building". The student provided a different, and also correct answer: "Take the barometer to the top of the building. Attach a long rope to it, lower the barometer to the street, then bring it up, measuring the length of the rope. The length of the rope is the height of the building."

The examinator and Calandra, who was called to advise on the case, faced a moral dilemma. According to the format of the exam, a correct answer deserved a full credit. But issuing a full credit would have violated academic standards by rewarding a student who had not demonstrated competence in the academic field that had been tested (physics). None of two available options (pass or fail) was morally acceptable.

Calandra asked the student the same question, and received a wealth of different answers including dropping the barometer from the top of the building, timing its fall with a stopwatch, trading the barometer to the building's superintendent in return for the information wanted, creating two small pendulums and measure the variation of g from the ground to the top of the building, creating a pendulum as high as the building and measuring its period, comparing the building's and the barometer's shadows. The student ultimately admitted that he knew the expected "correct" answer but was fed up with the professors "teaching him how to think ... rather than teaching him the structure of the subject".