Thursday, August 30, 2018

LECTURE: What Is a Schedule of Reinforcement?

The following article is taken from https://www.verywellmind.com/what-is-a-schedule-of-reinforcement-2794864

What Is a Schedule of Reinforcement?

So what exactly is a schedule of reinforcement and how does it work in the conditioning process? A schedule of reinforcement is basically a rule stating which instances of a behavior will be reinforced. In some cases, a behavior might be reinforced every time it occurs.
Sometimes, a behavior might not be reinforced at all.
Either positive reinforcement or negative reinforcement might be used, depending on the situation. In both cases, the goal of reinforcement is always to strengthen the behavior and increase the likelihood that it will occur again in the future.
You can get a better feel for how reinforcement schedules operate by thinking about how learning takes place in both naturally occurring learning situations as well as more structured training situations. In real-world settings, behaviors are probably not going to be reinforced each and every time they occur. For situations where you are purposely trying to train and reinforce an action, such as in the classroom, in sports, or in animal training, you might opt to follow a specific reinforcement schedule.
As you'll see below, some schedules are best suited to certain types of training situations. In some cases, training might call for starting out with one schedule and switching to another once the desired behavior has been taught. Certain schedules of reinforcement may be more effective in specific situations.
There are two types of reinforcement schedules:

Continuous Reinforcement Schedules

In continuous reinforcement, the desired behavior is reinforced every single time it occurs. This schedule is best used during the initial stages of learning in order to create a strong association between the behavior and the response.
For example, imagine that you are trying to teach a dog to shake your hand. During the initial stages of learning, you would probably stick to a continuous reinforcement schedule in order to teach and establish the behavior. You might start by grabbing the animal's paw, performing the shaking motion, saying "Shake," and then offering a reward each and every time you perform this sequence of steps. Eventually, the dog will start to perform the action on his own, and you might opt to continue reinforcing every single correct response until the behavior is well established.
Once the response if firmly attached, reinforcement is usually switched to a partial reinforcement schedule.

Partial Reinforcement Schedules

In partial or intermittent reinforcement, the response is reinforced only part of the time. Learned behaviors are acquired more slowly with partial reinforcement, but the response is more resistant to extinction.
For example, think of our earlier example where you were training a dog to shake. While you initially used a continuous schedule, reinforcing every single instance of the behavior may not always be realistic. Eventually, you might decide to switch to a partial schedule where you provide reinforcement after so many responses occur or after so much time has elapsed.
There are four schedules of partial reinforcement:
Fixed-ratio schedules are those where a response is reinforced only after a specified number of responses. This schedule produces a high, steady rate of responding with only a brief pause after the delivery of the reinforcer. An example of a fixed-ratio schedule would be delivering a food pellet to a rat after it presses a bar five times.
Variable-ratio schedules occur when a response is reinforced after an unpredictable number of responses. This schedule creates a high steady rate of responding. Gambling and lottery games are good examples of a reward based on a variable ratio schedule. In a lab setting, this might involve delivering food pellets to a rat after one bar press, again after four bar presses, and a third pellet after two bar presses.
Fixed-interval schedules are those where the first response is rewarded only after a specified amount of time has elapsed. This schedule causes high amounts of responding near the end of the interval, but much slower responding immediately after the delivery of the reinforcer. An example of this in a lab setting would be reinforcing a rat with a lab pellet for the first bar press after a 30-second interval has elapsed.

Variable-interval schedules occur when a response is rewarded after an unpredictable amount of time has passed. This schedule produces a slow, steady rate of response. An example of this would be delivering a food pellet to a ​rat after the first bar press following a one-minute interval, another pellet for the first response following a five-minute interval, and a third food pellet for the first response following a three-minute interval.