The Scientific Method
A Case History
Not all scientists follow the same path in solving problems, nor does the same person
solve problems in the same way each time. There are, however, methods that are common
to most problem solving. This is true even if the problems are everyday rather than
In December 1984, an engineer who worked at a nuclear power plant in Pennsylvania ran
into just such an “everyday” problem. The first time the engineer stepped into the
plant’s radiation detector, it buzzed and its red light went on. This meant he was
contaminated with radiation. Day after day he would set off the alarm. Each time he
would have to sit in the decontamination room. After four to six hours, the radiation
would decrease to safe levels, and he could leave.
The engineer tried to figure out the source of the radiation. He thought about where
he had been in the plant each day. The location did not seem to matter. Each time he
walked through the radiation detector, the alarm went off. After this had gone on for
about two weeks, he had an idea. Perhaps the contamination was not from the power
plant at all. He tested this idea by going directly from his car to the detection device
when he reported to work. It buzzed. He was not getting the radiation at work.
Only half the problem was solved, however. Where was he getting the radiation? His
first guess was his house. Experts in radiation measurement went to his house and found
extremely high levels of radon, a radioactive gas. This finding led the experts to further
questions. What was the source of the radon? Was the source inside or outside the
house? The experts decided to test other homes in the area. They tested over 2000
houses. More than 800 were found to have high levels of radioactivity. These led them
to suspect an outside source.
The experts studied the area further and found the radiation source. The houses were
located over rocks containing uranium. Radon is produced when atoms of uranium break
down. It was radon in the air of his home that caused the engineer’s problem with
1. Using only the first three paragraphs, identify the problem to be solved, how the
engineer gathered data needed to solve the problem, his hypothesis, how he tested
his hypothesis and the conclusion he drew from the experiment.
2. What was the final conclusion to the problem?
3. Did the final conclusion solve the engineer’s problem? Why or why not?