ICAN home about ICAN Tour Modules Glossary Search  
Your Path: ICAN Home > Modules > Behavioral Interventions > Differential Reinforcement: Lecture Page 3
Characteristics assessment Academic Interventions Behavioral Interventions Communication Interventions Environmental Interventions Sensory Interventions Social Interventions

1 2 3 4 5

Differential Reinforcement of Other Behavior (DRO)

Forum References FAQ's Quiz Lecture Introduction In previous section, we cautioned that the too frequent use of reinforcement may lead to growing tired of the reinforcement, resulting in a loss of reinforcement effectiveness (a situation known as satiation). In some situations, it does not make sense to give reinforcement every time the desired behavior occurs. Indeed, learning to perform a particular behavior requires that the behavior often be performed in the absence of reinforcement. Thus, a critical aspect of teaching involves arranging a schedule as to when to use of reinforcement and how often. There are three primary methods to do this. This section teaches us about the first one.

Example:

Claire is a 4-year-old child who has a diagnosis of autism. She attends a preschool program operated by the local school district. Every morning, Claire enters the classroom and for the first half hour engages in solitary play with the instructional materials on the floor mat. After about 20 minutes and as the other children are playing, Claire often tries to take the materials the other children are playing with. If they refuse to give them up, Claire hits them. She engages in this behavior of hitting pretty routinely in the mornings. When it happens, Ms. Pucket, her teacher, has to intervene and remove Claire to the other side of the classroom. This angers Claire and causes her to engage in even more severe displays of hitting. Ms. Pucket and the classroom aides don’t know what to do. They have tried giving her other materials. They have tired talking to her. They have even tried having her play in the corner by herself. But Claire is intent on taking the materials away from her peers.

What’s going on here?

In trying to explain Claire’s behavior, It may be that she is interested in her peers and wants to interact with them, but does not have the necessary social skills to do so in a manner that the other children find reinforcing. Or, maybe she does not know how to obtain new materials from the shelves and sees the materials her peers are playing with as “reasonable” choices for her. At this point in our analysis, all we know is (a) what she is doing, (b) how her peers respond, and (c) what the teacher does both prior to and after Claire’s response of hitting.

1. Definition

Differential Reinforcement of Other Behavior (DRO) is a procedure where positive reinforcement is provided only when the target behavior is not displayed for a specified period of time. Thus, when using a DRO procedure, reinforcement is provided for the zero occurrence of the target behavior (it is sometimes also called differential reinforcement of zero rates of behavior.) In future lectures we will discuss differential procedures for the gradual reduction of target behavior. But, in DRO, reinforcement is provided when there is no occurrence of the undesired behavior for a specified period of time.

DRO is perhaps the simplest of all behavior reduction procedures. You are merely reinforcing the absence of any misbehavior. All you do is determine whether or not the undesired target behavior occurred during a specified interval of time. If it occurred, reinforcement is withheld. If the target behavior did not occur, reinforcement is provided at the end of the designated interval. In either case, DRO involves differential delivery of reinforcement for not displaying certain predetermined target behaviors.

There are two advantages of using a DRO procedure:

  1. It is easy for teachers to use in most classrooms and school settings.
  2. You are working directly with the undesired target behavior by reinforcing its absence.

However, there are also two distinct disadvantages to using a DRO procedure:

  1. DRO procedure is not designed to teach and/or increase any particular appropriate behavior. It merely reinforces the absence of certain behaviors.
  2. When using a classic DRO procedure, you run the risk of reinforcing undesired behaviors since reinforcement is given at the end of an interval provided that the targeted undesired behavior has not occurred. This leaves you open to reinforcing other types of inappropriate behaviors.

2. Variations when using a DRO procedure

There are at least three variations to keep in mind when using DRO. First, reinforcement is made contingent on the non-occurrence of the target behavior throughout the specified period of time. For example, reinforcement is given only when Claire does not hit her peers during any 8-minute period of time (see #3B below for determining how to specify this interval). In another example, when using DRO for not getting out of his seat, John is told, “If you do not get out of your seat during our English lesson (40 minutes long), you can be at the head of the lunch line.” If the student meets this contingency (if Claire does not hit her peers, or if John does not get out of his seat during English), the reinforcer will be given. Delivery of a reinforcer is made only after no instances of the target behavior occur during the entire interval.

Second, in many instances, it is desirable to break down sessions into smaller intervals of time. For example, it may be desirable to reinforce Claire every 5 minutes for not displaying the target behavior of hitting. Similarly, we may want to reinforce John during the English lesson rather than wait until the end of the period. Or, in the case of Dana in Lecture 1, the teacher provided coupons to Dana (reinforcement) each time he saw her working with her peers during the science lesson. In these situations, it may be wise to provide reinforcement during smaller intervals of time within the period.

Third, the teacher may want to use DRO for completing specified academic work. For example, if a student is completing an in-class writing assignment, the teacher may give a sticker or a happy face on her paper only when it is handed in with no doodles (a pre-determined target behavior).

3. How to use DRO effectively

Although DRO is a relatively simple procedure to use, there are four issues to consider to ensure its effectiveness. All involve how often to schedule reinforcement.

  1. Baseline data must be obtained not only to keep track of how often the target behavior is occurring, but also to decide how often the DRO procedure should be scheduled. Selection of a proper time interval is absolutely critical, and should be established by collecting data and not set arbitrarily. During baseline, the time between responses of the undesired behavior is recorded and a slightly smaller interval should be selected to determine when to give the reinforcement.

    For example, Claire’s teacher—Ms. Pucket—collected baseline data for three days. She recorded the time of day when Claire entered the classroom and the time of day when she hit the, on average, Claire went 15 minutes before she hit one of her peers. Thus, the schedule for the DRO was set at every 8 minutes, an interval about half as short as the average baseline level.
  2. A criterion for increasing the DRO interval should be established. Suggestions include:
    • Start at a small enough interval so that the student can earn more reinforcement for not engaging in the target behavior than for displaying it. Typically, this interval should be one half as short as the average baseline level.
    • Lengthen the interval over time. This decision should be based upon the data being collected indicating the success the student is having at each interval length.
  3. Two other decisions need to be made prior to implementing a DRO:
    • a. Whether to reset the DRO interval following a response occurrence or to wait until the next scheduled interval, and
    • b. Whether to respond to the undesired behavior in any other way or just ignore it.

    In Claire’s situation, the teacher clearly cannot ignore the hitting and, therefore, must respond in some manner. This risk here is that Claire may be obtaining some reinforcement from the teacher’s intervention, thus potentially minimizing the effectiveness of the DRO.

  4. As noted above, one limitation of a DRO procedure is that if properly implemented, you may inadvertently reinforce behaviors that are undesirable. For example, Claire may scream first to get the attention of a peer. Or, she may knock over materials that a peer was playing with. In either case, so long as she did not hit a peer, Claire would receive reinforcement at the end of the specified interval. Thus, a fourth rule may apply.
  5. A decision must be reached before the intervention is begun that outlines whether reinforcement will be given regardless of which behaviors (other than the target) are displayed, or whether reinforcement will be withheld when certain other inappropriate behaviors occur during the interval.
In the above example, it may be determined ahead of time that any aggressive behaviors will result in the interval being extended without reinforcement (see #3 above). So, if the target behavior is “hitting,” and during the interval Claire pushes her peer, she would not receive reinforcement during that interval. The problem is that Claire may not receive sufficient reinforcement during the interval to allow discrimination to occur as to when and under what condition she will receive reinforcement. Thus, the DRO procedure may lose its effect.

We will address this issue in the next lecture when we talk about using another differential reinforcement procedure. Let us simplify it for Claire and assume that she does not display any other inappropriate behaviors and that a DRO is still an effective intevention.

4. An implementation example

Using our example of Claire, let’s see if we can design a program using the considerations noted above.

Since Ms. Pucket had already determined through her baseline data that on average, Claire played for 15 minutes before she hit one of her peers, she had already set the DRO schedule to 8 minutes. That is, if Claire did not hit any of her peers during the first 15-minute period, she would receive a reinforcer.

Now, prior to the start of the DRO, Ms. Pucket had to determine a powerful reinforcer to use. She could not just randomly select a reinforcer, since she needed to know what Claire found reinforcing. Using a reinforcement sampling technique, Ms. Pucket learned that stroking the back of Claire’s neck was a very powerful reinforcer for her.

Ms. Pucket next had to determine when she could implement the procedure. Although a DRO procedure is relatively easy to use, it does take some time. So Ms. Pucket looked at the classroom schedule. She noted that during the first hour of the morning, and her classroom aide were both in the classroom. By mid-morning, the aide took two children to the physical therapist and therefore was not available. The aide returned just before lunch, so both were available for the remainder of the day. Thus, the DRO procedure could be implemented during the first hour of the morning, during lunch and for about one hour after lunch.

Next, Ms. Pucket made the classroom aide responsible for the DRO procedure. By assigning the aide to implement the DRO, Ms. Pucket eliminated a common problem with this procedure: inconsistent implementation. The aide kept track of the 8-minute interval by using her wristwatch.

Then, Ms. Pucket made sure that Claire had available all the play materials she enjoyed. In this way, Ms. Pucket maximized the opportunity for Claire to receive reinforcement every 8 minutes.

After one week of implementation, the data showed that Claire was no longer hitting her peers during the first hour of the day. It also showed that she was receiving reinforcement (neck strokes) every 8 minutes, for a total number of eight neck strokes in the first hour. However, during mid-morning (when the aide was out of the classroom), the data showed that hitting increased to a rate of about once every 22 minutes. While this was considered an improvement over baseline (which showed hitting on average of once every 15 minutes), Ms. Pucket had to find another approach during these times. Finally, during the 30-minute lunch period and for the hour after lunch (when the aide had returned to the classroom), the data showed that, like in the morning, hitting was eliminated. Again, Claire received neck strokes every 8 minutes during these intervals, for a total of 12 neck strokes for the entire interval.

After the first week, Ms. Pucket increased the interval to 10 minutes, then 12 minutes, and then 15 minutes over the next three weeks. Claire responded beautifully, maintaining a zero level of hitting throughout. However, she continued to demonstrate hitting during the time the aide was out of the classroom, but at a much lower rate than baseline.

Ms. Pucket was pleased with these results, but was left with questions. What procedure could she implement during the time the aide was out of the classroom? If hitting was an attempt by Claire to engage—although unsuccessfully—in social interaction with her peers, what behaviors could she teach her that would function as a successful interaction? We will learn the answers to these questions in the next section.

5. A Summary

We have explored the use of differential reinforcement of other behavior (DRO) as a relatively easy and effective tool for reducing and eliminating undesired target behaviors. We noted several advantages of using DRO, including its ease of use and the fact that it allows us to work directly with the undesired target behavior by reinforcing its absence. However, we also discussed several drawbacks to the use of DRO procedure, including not teaching any specific appropriate behavior and the possibility of reinforcing undesired behaviors. We next discussed variations in using a DRO, including setting the interval length. Then we talked about four issues to consider when planning to use a DRO procedure: (a) taking a baseline to establish interval length, (b) using a pre established criterion for increasing the interval length, (c) making some decision rules about when and under what conditions which behaviors will be reinforced and (d) deciding under what conditions the interval will be reset. An implementation example was discussed to illustrate some of these principles in action. Questions posed at the end were left unanswered until the next lecture on the use of differential reinforcement of incompatible behaviors.

 

1 2 3 4 5