Fixed-Interval Schedule

A fixed-interval schedule is a type of reinforcement schedule in operant conditioning where a behavior is reinforced after a fixed amount of time has elapsed since the last reinforcement.

Definition

In a fixed-interval schedule, the timing of reinforcement remains constant, regardless of the behavior being exhibited. For example, imagine a scenario where a researcher wants to reinforce a rat every 5 minutes. If the rat presses a lever 3 minutes after the last reinforcement, it will not receive any reinforcement until the next 5-minute interval has passed.

Characteristics

Fixed-interval schedules have several notable characteristics:

• Timing: Reinforcement occurs after a fixed amount of time has elapsed since the last reinforcement.
• Response pattern: Initially, there is often a low rate of responding immediately after reinforcement. However, as the time for the next reinforcement approaches, the response rate increases.
• Scalloped response pattern: The response pattern on a fixed-interval schedule often resembles a scallop shape when plotted on a graph, with a slow and steady increase in responding as the interval nears its end.
• Post-reinforcement pause: Following each reinforcement, there is typically a pause in responding until the next reinforcement becomes available.

Examples

Fixed-interval schedules can be observed in various real-life situations:

• A student studying for an exam for a fixed amount of time each day, regardless of their study performance, and being rewarded with a break when the time is up.
• Workers in a factory receiving wages every two weeks, regardless of their productivity during that period.
• A monthly paycheck received for completing a regular job, knowing that the reinforcement will come after the same fixed interval.

Advantages and Disadvantages

Fixed-interval schedules have both advantages and disadvantages:

• Advantages: They can establish consistency and predictability in various fields such as work, education, and personal habits. They can also promote regularity and discipline.
• Disadvantages: Fixed-interval schedules can result in a decrease in motivation and productivity immediately after reinforcement, as well as the possibility of engaging in sparse responding until the reinforcement is due.