Schedules of Positive Reinforcement

One of the most important contributions of B. F. Skinner to training theory was the elucidation of various reinforcement schedules and their differential impact on the performance of learned behavior (Ferster and Skinner, 1957). In dog training, reinforcement is provided according to various plans and schemes depending on the specific requirements of the training objective. During the early stages of training, a new behavior is reinforced every time it occurs. The new behavior is acquired on a continuous schedule of reinforcement (CRF). Once a stable operant level is obtained, the behavior is usually brought under the control of an intermittent schedule of reinforcement. Intermittent schedules require a dog to emit a prerequisite number of responses (ratio schedule), emit at least one response within a predetermined period of time (interval schedule) before reinforcement is delivered, or emit the target behavior continuously over some period of time (duration schedule). All three schedules can be either fixed or variable. In combination, therefore, three basic schedules of fixed and variable reinforcement are possible: (1) fixed and variable ratio (FR/VR), (2) fixed and variable interval (FI/VI), and (3) fixed and variable duration (FD/VD).

An FR schedule of reinforcement requires that a dog emit a fixed number of responses before reinforcement is presented. For example, requiring a dog to sit three times before giving it a treat is an FR 3 schedule of reinforcement. A VR schedule is set according to an on-average occurrence of reinforcement. For example, a dog reinforced randomly on the first, third, or fifth time it happens to sit would be maintained on VR 3 schedule of reinforcement. Interval and duration schedules are also applied on a fixed or a variable basis. For instance, an interval schedule only requires that the dog sit at least once during some fixed or variable period of time. On the other hand, a duration schedule involves a fixed or a variable length of time during which the response must be continuously emitted before reinforcement is delivered. A common example in dog training that utilizes a duration schedule is the stay exercise. A dog required to sit and stay for a period of 30 seconds before being reinforced is working on an FD 30s schedule of reinforcement. If the dog is required to sit for varying lengths of time, but on average for a 30-second duration, then the dog is working on a VD 30s schedule.

An important benefit of intermittent reinforcement is that it makes the selected behavior more resistant to extinction. While a CRF schedule will result in fast, steady acquisition, if reinforcement is suddenly withdrawn, the learned behavior will extinguish with a corresponding rapidity. The foregoing reinforcement schedules outlined require that a dog emit more responses for the same amount of reinforcement. The effect is to "immunize" the learned behavior against extinction should reinforcement not always be forthcoming. Not only do the various schedules (especially the VR schedule) cause instrumental behavior to become more resistant to extinction, they also stimulate dogs to work even harder for a comparatively smaller rein-forcer. This added benefit allows for an easy transition from tangible rewards like food to less tangible social rewards like petting and praise. When food is used during the acquisition phase, it is usually faded as soon as possible and replaced with various social rewards sufficient to maintain the learned behavior. Finally, intermittent schedules are very important in shaping procedures where a previously established approximation must give way to the next step in the program of contingencies without causing the dog to quit.

How To Train Your Puppy

How To Train Your Puppy

Getting a new puppy is a fun and interesting time. You probably went to a breeder or pet store or maybe just saw an ad on the Internet or the newspaper, for puppies, and decided just to check it out. Before you knew it those little eyes and fluffy puppy fur had your heart melting and you were headed home with him or her in your arms. If you are like most new pet owners you had visions of playing fetch with your dog, of watching him frolic at the lake, and of cuddling up on cold nights.

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