USING THE MARKING STIMULUS
The use of a conditioned reinforcer has been a staple of animal behavior modification. However, recent evidence has
brought into question whether the supposed conditioned reinforcer is ACTUALLY functioning as a predicationstimulus, rather than a conditioned reinforcer. Studies have shown that the behavior of animals during training are
different than those seen in laboratory studies. Until more research is conducted, the consensus is that our “conditioned
stimulus” shares properties of both, but functions as a marking stimulus in context of training new behaviors. The
stimulus we will use are “Yes!’” and clickers. “Yes!” may be used when multiple dogs are within hearing distance of the
clicker.
CONDITIONED REINFORCER: A conditioned reinforcer is a previously neutral stimulus that has been paired with a
primary reinforce. It acquires the same reinforcement properties associated with the primary reinforcer. For example,
when a sound (e.g., clicker) in the environment has been associated with food, that sound will elicit the same effects as
the presentation of the food. Consequently, the stimulus (e.g. clicker) will come to reinforce behavior similar to the food.
Conditioned reinforcers are extremely powerful and helpful in training; they are, in essence, the magic behind good
training.
MARKING STIMULUS: When a sound (or other stimuli that are short in duration, unique to the environment, neutral,
and reliably produced) is predictive of reinforcement, it will signal that the response performed will be reinforced. This is
different than a conditioned reinforcer because the stimulus itself does not take on a conditioned value. Think of it as
signaling, “Reinforcer is coming!” These stimuli PREDICT a reinforcer is on the way, thus can be used to MARK when
the appropriate response occurs, even if the trainer is not in view of the animal. The marking stimulus is the key to getting precise
results!
HOW TO PAIR THE “YES”/CLICKER WITH A TREAT: Introducing the neutral stimulus to the dog is the first
exercise you should do with a new dog. To do this, simply say “Yes!’” or click and give the dog a treat, regardless of his
behavior (Noncontingent Reinforcement, NCR). Repeat this five to ten times or until the dog is readily responding to
the “Yes!’”/ the click. Complete this exercise each time YOU work with the dog even if the dog has been worked with by
other students. Be careful not to become a treat conveyer-belt. To prevent a dog from “expecting” treats based on
temporal cues, insert various pauses between NCR trials to strengthen the predictive value of the “Yes!”/click.
THE MARKING STIMULUS AS A BRIDGE: In training, a marking stimulus is also called a bridge because it bridges
the time gap between when the dog performs the behavior and when you can physically hand him a treat. A bridging
reinforcer can serve you in training by reinforcing the exact behavior without risking accidently reinforcing other
behaviors during the delay in distributing the primary reinforce (the treat)—it allows you to precisely mark the behavior
you are teaching it as he is performing it. Because the bridge helps the trainer to reinforce the dog's behavior at exactly
the proper instant, the bridge will consequently become a sound that tells the dog exactly which thing he doing that is
the response to repeat in the future. The bridge is not a sound that tells the dog he has done what you want him to do, it is
a sound that tells the dog he is doing what will be reinforced. To use a bridge effectively you must use the Yes!" / click as
the dog is performing the precise response.
Hint: Imagine you’re taking a picture of the dog’s behavior but instead of pressing a camera button, you say “Yes” or press
the clicker as the behavior occurs.
© 2013 Engebretson, Watson and Sobie. This publication may be duplicated and distributed for non-commercial purposes, provided
that full and clear credit is given to the authors with appropriate and specific direction to the original content.
A WORD ON SHAPING VS FADING BEHAVIOR
SHAPING BEHAVIOR:
An obvious necessity for dog training is that a dog needs to know how to do the behavior you want him to perform.
Some behaviors will not just appear the way you want them; instead, you have to build or shape them. Shaping modifies
behavior by reinforcing behaviors that progressive approximate the target behavior. Shaping can be used to train dogs to
perform behaviors that would rarely if ever occur otherwise.
As a trainer you work to successively catch bits of behavior that more and more closely resemble the actual behavior you
desire. Shaping is best when there is lots of variability in a dog’s behavior. Be warned: if you progress along the
approximations too slowly, you will limit the variability in behavior; however, if you progress too fast you may extinguish
the behavior. Shaping is a fluid process. In addition, shaping can be used to change the frequency, timing or intensity of a
behavior.
FADING A LURE/PROMPT:
Like shaping, fading can be used to establish a response to a cue that a dog is not readily responding to. The overall goal
of fading is to have the dog perform the behavior upon the desired cue, and not upon the presentation of the prompt. As
the dog becomes more proficient at a particular prompt level, the prompt is faded to a less intrusive prompt. Eventually,
you have shifted stimulus control from one stimulus (the prompt) to another. Examples are when you use physical
guidance or modeling. In the context of this class, most of our prompts will be lures using treats.
© 2013 Engebretson, Watson and Sobie. This publication may be duplicated and distributed for non-commercial purposes, provided
that full and clear credit is given to the authors with appropriate and specific direction to the original content.