What happens at the end of a time interval in interval schedules of reinforcement?

In interval schedules of reinforcement, the key feature is that reinforcement is available only after a specific time period has elapsed. When the time interval ends, the first response that occurs after this interval is what gets reinforced. This structure encourages the behavior to occur more frequently as the subject learns that reinforcement is contingent upon responses made after the completion of the time period.

The rationale behind this type of schedule is that it emphasizes timing; subjects must wait for the interval to finish before their behavior can be rewarded. This fosters a consistent behavior pattern as the subject becomes adept at timing their responses to align with the end of the interval, ultimately shaping their response frequency and timing.

Understanding this mechanism helps clarify why other options don't align with the principles of interval schedules. For instance, rewarding all responses during the interval would contradict the very essence of an interval schedule, which relies on the timing of the first response after the interval. Similarly, claiming no reinforcement is given overlooks the fact that reinforcement is indeed provided, just selectively after the interval. Lastly, randomness in reinforcement does not apply, as interval schedules are deterministic regarding when a response can earn reinforcement.