John was determined to do well on the fi nal biology exam, so he studied from 10:00 p.m. to 2:00 a.m. each night for the two weeks before the test. To keep awake, he drank strong coffee. The night...

John was determined to do well on the fi nal biology exam, so he studied from 10:00 p.m. to 2:00 a.m. each night for the two weeks before the test. To keep awake, he drank strong coffee. The night before the 8:00 a.m. exam, he made sure he got a good night’s sleep, but he did not do nearly as well on the test as he expected. What explanation can you offer? Describe how you could test the accuracy of your explanation.