S was invited to be an examiner of a vocational education school. He was honored.
The examination was simple. The students were instructed to examine a wheel of a car. They were expected to perform Test A, Test B and Test C.
The examination was fool-proof. The headmaster excitedly explained that the students had already undergone a rehearsal of the examination the week before. Besides, to ensure they would not say something silly, the students were informed that the wheel at the examination must be normal. They only needed to report Test A, Test B and Test C were negative. As a note of caution, the headmaster also advised the examiners to remind the students should they miss any tests.
S glanced at the marking sheet and was taken aback. There was one mark allocated to each of the following five steps: Entering the room, Test A, Test B, Test C, and leaving the room.
“Are we not supposed to mark the skills of performing Test A, Test B and Test C?” asked S.
“No,” the headmaster answered, “please just give full marks if a student has performed all three tests. But remember, some students may be nervous and forget one of the tests. In that case, give them a gentle reminder.”
“How then can we assess their skills? It is impossible not to get full marks.”
“This is not the purpose of this examination,” the headmaster replied. S felt he suddenly understood the purpose and decided not to ask anymore.
The examination was extremely smooth and efficient. Students confidently reported that Test A, Test B and Test C were negative, some even before finishing the tests. S was bored and tried to entertain himself by asking the students what could be wrong if only Test C was positive. Though none of them could answer, S understood they were not trained to read positive results and did not want to violate the marking instructions. He gave all of them five marks anyway.
Soon, the last student came in. S gave him one mark for entering the room and instructed him to start. To his surprise, he performed Test A and Test C swiftly and stopped.
“Have you completed the examination?” S dutifully reminded him.
“Yes,” the boy answered, “Test A and Test C were negative.”
“Would you like to perform Test B?” S asked explicitly. It really did not matter. He had given full marks to all students that day anyway.
“No, for this type of wheel, Test A and Test B always give the same results.”
S was sad. Although he could name a special situation in which Test A and Test B would have different results, the boy knew what he was doing but might end up at the bottom of the class.
In the end, S was determined. “You are right. Please just perform Test B for the sake of checking your skills.”