Final answer:
Leon's study pattern before exams corresponds to a fixed-interval reinforcement schedule, where studying increases as the exam date approaches due to the predictable nature of the exams occurring every third week.
Step-by-step explanation:
Leon will probably study the most just before an exam and the least just after an exam due to the influence of a fixed-interval reinforcement schedule. This schedule provides reinforcement at fixed intervals, in Leon's case, every third week with an exam. As a result, the behavior of studying increases as the exam approaches, reflecting a scallop-shaped response pattern where there is a significant pause after reinforcement, followed by a gradual increase in behavior until the next reinforcement is due.
Positive reinforcement is key in such patterns, and it is most effective when provided immediately after the desired behavior is demonstrated to strengthen the association between behavior and reward. For example, a treat is given every time a dog sits. However, with fixed intervals like Leon's exam schedule, the behavior occurs more frequently as the exam date nears, indicating an understanding of the pattern of reinforcement and a response to the anticipation of the next 'reward'—the completion of an exam.