Final answer:
Shauna experiences a fixed interval reinforcement because she gets a bonus at the end of each pay period she is not late, making the reward both predictable and time-based.
Step-by-step explanation:
The reinforcement schedule Shauna experiences for being on time for work is an example of a fixed interval reinforcement. This schedule operates under the principle that behavior is rewarded after a set amount of time—in Shauna's case, every pay period in which she is not late. Since the interval at which the reinforcement (bonus) is received is fixed and predictable, occurring at the end of each on-time pay period, it matches the criteria for this type of schedule.
Unlike variable ratio reinforcement, where the number of responses needed before a reward can vary, or variable interval reinforcement, where the time between reinforcements is unpredictable, fixed interval reinforcement schedules are predictable and set based on a timetable. Positive reinforcement is at play here because an appealing stimulus (the bonus) is being added to increase the likelihood of Shauna's punctual behavior.