Resources for unit 3

1.7. Partial and continuous reinforcement

One way to expand the use of operant learning is to modify the schedule on which the reinforcement is applied. There are two main types of reinforcement schedules: continuous reinforcement and partial reinforcement.

• In continuous reinforcement, the desired behavior is reinforced every time it occurs. For instance, whenever the child gets good marks, he/she gets a biscuit.  A student receives praise every time they turn in their homework on time. Continuous reinforcement results in relatively fast learning but also rapid extinction of the desired behavior once the reinforcer disappears. The problem is that because the organism is used to receiving reinforcement after every behavior, the responder may give up quickly when it doesn’t appear.
• In partial reinforcement, the desired behavior is reinforced only some of the time, not every time it occurs.  Partial reinforcement occurs at irregular intervals: the responses are sometimes reinforced, and sometimes not. A student may receive praise for their behavior occasionally, but not every single time they act appropriately.  A student might be given a reward (like extra recess time or a privilege) on an unpredictable schedule, making it less predictable when they will earn it. This encourages the behavior to continue because the student is unsure when the next reward will come.

The four types of partial reinforcement schedules

Partial reinforcement schedules are determined by whether the reinforcement is presented on the basis of the time that elapses between reinforcements (interval) or on the basis of the number of responses that the organism engages in (ratio).  These are:

•        Fixed-ratio schedule

•        Variable-ratio schedule 

•        Fixed-interval schedule

•        Variable-interval schedule

In a fixed-ratio schedule, a behavior is reinforced after a specific number of responses or reinforcement is provided after a set number of responses or behaviors. For instance,

•        A student gets a small prize of a pen for example after completing 5 math problems correctly.

•        A student receives a notebook after every 10 books they read or after every 10 assignments they complete.

This type of reinforcement leads to a high rate of response, as students know exactly what they need to do to get the reward. However, once the student earns the reward, they might take a short break before resuming work, as the reinforcement is predictable.

A variable-ratio schedule provides reinforcers after a specific but average number of responses or Reinforcement is provided after an unpredictable number of responses or behaviors. The number of responses needed to get reinforced varies around average. A teacher randomly praises a student after an unpredictable number of correct answers or positive behaviors. For instance, they might praise a student after 3, 5, or 8 correct answers in class, but the praise is not given on a set schedule.

This type of reinforcement tends to create a high, stable rate of responding because students never know when the reinforcement will come, keeping them motivated to engage continuously. Ratio schedules tend to produce high rates of response because reinforcement increases as the number of responses increases.

In a fixed-interval schedule, reinforcement occurs for the first response made after a specific amount of time has passed or reinforcement is provided after a fixed amount of time has passed, regardless of the number of responses or behaviors. Examples:

•        Weekly quiz: Every Friday, the teacher gives a quiz on the material studied during the week. Students are reinforced (either through a grade or verbal praise) for their performance on the quiz, regardless of how many answers they get correct.

•        Time-based rewards: After a specific time interval (e.g., every 30 minutes), the teacher gives a short break to students who have been working steadily during that period.

Students may exhibit bursts of activity as the time for reinforcement approaches, but there may be a decrease in activity right after the reinforcement. For example, there might be a burst of study efforts just before the quiz. Most students study for exams in the same way.

In a variable-interval schedule: the reinforcers appear on an interval schedule, but the timing is varied around the average interval, making the actual appearance of the reinforcer unpredictable or Reinforcement is provided after a variable amount of time has passed, with the time interval varying around an average. A teacher might give short quizzes throughout the week, but the students don't know when these quizzes will happen. Since the reinforcement (in this case, grades or praise after each quiz) comes at random intervals, students tend to stay prepared and engaged.  Quizzes are given at unpredictable intervals, so students don't know when to expect one. The timing of the quizzes varies. A teacher might randomly check whether students are on task during independent work. The student doesn't know when the teacher will come around, so they remain focused and keep working in case the teacher checks in. A teacher might provide praise or a small reward at random times throughout the lesson. For example, a student who consistently contributes to class discussions might receive praise, but the teacher does not follow a set schedule for when to provide it.

Interval reinforcement schedules tend to produce slow and steady rates of responding. This schedule encourages consistent and steady behavior, as students know they will eventually receive reinforcement, but they are unsure of exactly when it will occur. This can lead to higher levels of sustained engagement, as students remain attentive and active in anticipation of reinforcement.