A DRL procedure, or Differential Reinforcement of Low Rates of responding, is a behavior intervention technique designed to reduce the frequency of a specific behavior without eliminating it entirely. It works by reinforcing an individual when they engage in the target behavior at a lower rate than before, or when a longer period of time passes between instances of the behavior.
Understanding Differential Reinforcement of Low Rates (DRL)
At its core, DRL is a form of differential reinforcement, meaning it selectively reinforces certain behaviors while withholding reinforcement for others. Specifically, DRL aims to lower the rate of a response by one of two primary methods:
- Reinforcing Fewer Incidents: Providing reinforcement if the behavior occurs at or below a predetermined number of times within a specific period.
- Reinforcing Longer Time Intervals: Delivering reinforcement if a minimum amount of time has elapsed since the last occurrence of the behavior.
This approach is particularly useful for behaviors that are acceptable or even desirable at low frequencies, but problematic when they occur too often. For instance, contributing to class discussions is good, but monopolizing the conversation is not. DRL seeks to find that appropriate balance.
How DRL Procedures Work
DRL procedures function by making reinforcement contingent on the rate of a behavior. Instead of reinforcing the absence of a behavior (as in Differential Reinforcement of Other behavior - DRO) or a completely different, more appropriate behavior (as in Differential Reinforcement of Alternative behavior - DRA), DRL focuses on decreasing the intensity or frequency of an existing behavior.
The implementer sets a criterion for the acceptable low rate. If the individual meets or falls below this rate, they receive reinforcement. If they exceed the rate, reinforcement is withheld. Over time, the individual learns to adjust their behavior to meet the new, lower frequency requirement to earn reinforcement.
Key elements of a DRL procedure include:
- Identifying the Target Behavior: Clearly defining the behavior to be reduced.
- Baseline Data Collection: Measuring the current rate of the behavior to establish a starting point.
- Setting a Criterion: Determining the new, lower rate at which reinforcement will be provided. This should be a gradual reduction from the baseline.
- Selecting Reinforcers: Identifying what motivates the individual.
- Consistent Implementation: Applying the procedure consistently and systematically.
Types of DRL Schedules
DRL procedures can be implemented using different schedules, each with its own approach to defining "low rates."
| Type of DRL Schedule | Description | Example |
|---|---|---|
| Full-Session DRL | Reinforcement is delivered if the total number of responses during an entire session or observation period is at or below a predetermined criterion. | A student who raises their hand excessively might receive a sticker at the end of a 30-minute lesson if they raised their hand 5 times or less during that entire period. |
| Interval DRL | The total session is divided into equal intervals. Reinforcement is delivered at the end of an interval if the number of responses within that interval is at or below a criterion. | During a 15-minute work period divided into three 5-minute intervals, a child receives a token after each 5-minute interval if they called out no more than once in that interval. |
| Spaced Responding DRL | Reinforcement is delivered if a minimum amount of time has elapsed between two consecutive responses. If the behavior occurs before the specified interval, a new interval begins. | A student who frequently asks "What time is it?" might earn a point if at least 10 minutes pass between their questions. If they ask again within 10 minutes, the timer resets. |
Practical Examples of DRL
DRL procedures are widely used in various settings, including schools, homes, and therapeutic environments, to modify behaviors that are acceptable in moderation.
- Classroom Participation: A teacher might implement a DRL schedule for a student who dominates class discussions. The student receives praise if they contribute no more than three times during a 20-minute discussion period. This encourages thoughtful contributions rather than constant talking.
- Repetitive Questioning: For an individual who asks repetitive questions (e.g., "Are we there yet?"), a DRL procedure might reinforce them for waiting at least 15 minutes between asking the same question.
- Food Consumption: In a therapeutic setting, a child who eats too quickly might be reinforced if they take at least 30 seconds between bites, thereby slowing down their eating pace.
- Leaving Seat: A student who frequently leaves their seat might be on an interval DRL, receiving a checkmark for each 10-minute interval they stay in their seat for the entire duration, and only leaving once per interval for a legitimate reason.
When to Use DRL vs. Other Procedures
DRL is distinct from other behavior reduction strategies because its goal is reduction, not complete elimination.
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Use DRL when:
- The behavior is acceptable or even desirable at a low rate.
- The behavior is not dangerous or severely disruptive.
- You want to teach the individual to moderate their behavior.
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Consider other procedures (like DRO or DRA) when:
- The behavior is dangerous, highly disruptive, or completely undesirable and needs to be eliminated.
- You want to replace an undesirable behavior with a specific, more appropriate one.
For more information on applied behavior analysis techniques, you can explore resources from organizations like the Association for Behavior Analysis International (ABAI).
Key Considerations for Implementation
Effective implementation of a DRL procedure requires careful planning and consistency:
- Gradual Reduction: Start with a criterion that is slightly lower than the baseline rate, then gradually decrease it over time to ensure success.
- Clear Expectations: Ensure the individual understands the target behavior, the new rate requirement, and what they need to do to earn reinforcement.
- Immediate Reinforcement: Provide reinforcement as soon as the criterion is met to strengthen the desired behavior.
- Monitor Progress: Continuously collect data on the behavior's frequency to track effectiveness and make adjustments as needed.
- Positive Reinforcement Focus: Emphasize what the individual can do to earn reinforcement, rather than solely focusing on the negative aspects of the behavior.
