A Brief Explanation of Applied Behavior Analysis. conditioning to identify the contingencies affecting a student s behavior and the functions of the

Transcription

1 A Brief Explanation of Applied Behavior Analysis Applied Behavior Analysis is the procedure for using the principles of operant conditioning to identify the contingencies affecting a student s behavior and the functions of the behaviors. Applied Behavior Analysis (ABA) is governed by the law of effect. The law of effect, which was developed by Edward Thorndike in 1905, states that a behavior followed by a pleasant consequence is more likely to occur in the future (reinforcement). Conversely, a behavior followed by an aversive consequence is less likely to occur in the future (punishment). The focus of ABA is on the presentation of consequences that will increase the likelihood of the behavior occurring in the future. ABA does not advocate the presentation of aversive stimuli to reduce the likelihood of a behavior (punishment). Instead, the discipline uses an extinction contingency, where the behavior to be reduced is no longer followed by a consequence. In the case of problem classroom behavior, the consequence would involve ignoring. However, the extinction contingency requires a concurrent reinforcement contingency to increase the likelihood of a desired classroom behavior to allow the student to achieve the same function. If an alternative behavior is not taught, the extinction contingency is likely to fail. In order for the contingencies to be effective, the consequence must immediately follow the student s behavior. This is to ensure that the consequence is associated with the target behavior and not a subsequent behavior. The presentation of the stimulus can be faded or paired with a natural consequence once the student has become more fluent in performing the behavior.

2 The two reinforcement contingencies that affect the increased likelihood of a student s behavior are: positive reinforcement and negative reinforcement. In behavioral psychology terms, positive indicates the presentation of a stimulus and negative refers to the removal of a stimulus. Reinforcement refers to the increased likelihood of the behavior occurring after the presentation of or removal of the stimulus. Positive reinforcement is defined as the increased likelihood of a behavior occurring after the presentation of a stimulus. This refers not to the actual stimulus, but to the affect on the behavior of a student. For example, when a student increases the amount of time on task following the presentation of an object, the contingency is defined as a positive reinforcement contingency. Negative reinforcement is the increase in the likelihood of a behavior occurring in the future following the removal of an unpleasant or aversive stimulus. For example, when a student stops banging his head when classwork is removed from his desk, the head banging will likely occur in the future in order to escape the aversive condition of desk work. Another example would be the increased likelihood of a screaming student to become quiet when removed from a loud or overstimulating classroom. The removal of the loud classroom (aversive stimuli) will increase the likelihood of student screaming in order to escape the aversive stimulus.

3 A caution in the use of a negative reinforcement strategy is the vicious circle of negative reinforcement. The student will scream to escape the unpleasant classroom and the teacher will continue to remove the student from the classroom in order to escape the screaming. ABA involves identification of both the function of the behavior (escape) and an alternative replacement behavior in order to teach the student a more appropriate and socially acceptable way (using visuals and/or first-then boards) to achieve the same function as the screaming. Therefore, the goal of an intervention would be to reduce the likelihood of screaming and to increase the likelihood of using a visual for communication. Negative punishment or penalty is also likely to be incorporated into a behavior change contingency. The strategy involves the removal of a pleasant stimulus and serves to decrease the likelihood of an inappropriate behavior occurring in the future. For example, when a student who has earned the computer begins to bang on the keyboard and the teacher removes the student from the computer. Another example of penalty is the use of lunch detention following inappropriate classroom behavior. Applied Behavior Analysis (ABA) involves the use of functional analysis to determine the contingency supporting the behavior. The contingencies supporting an increased likelihood of a behavior occurring in a similar condition are: negative reinforcement contingencies and positive reinforcement contingencies. The function supported by the positive reinforcement

4 contingency is obtaining a rewarding condition. The function supported by the negative reinforcement contingency is escape from aversive stimuli. Once the function of the problem behavior is determined, a socially acceptable replacement behavior can be identified. The replacement behavior should be a behavior that allows the student to achieve the same or similar function as the inappropriate behavior. The replacement behavior must be taught to the student and the progress toward acquisition tracked. There are three major techniques for teaching a student replacement behaviors. According to Kendra Cherry ( Downloaded on July 8, 2013), the three instructional methods used are: chaining, prompting, and shaping. Prior to instruction, the replacement behavior needs to broken down into teachable steps using a task analysis. The task analysis will provide both the instructional framework and a tool for instructional progress monitoring. Chaining involves teaching each step of the task analysis starting with either the first step or the last step in the behavior chain. One step of the chain is taught at a time and the student is guided through the rest of the steps. The steps are taught using a positive reinforcement contingency and teacher prompting and support. As the student becomes more fluent in performing the behavior, the teacher assistance is faded and the next step in the chain serves to support (reinforce) the newly learned step. The learned step then becomes a signal for beginning the next step in the chain, which will be prompted and reinforced by the teacher until it is learned. The completed chain will be governed by the natural consequence of the replacement behavior. A backwards chaining strategy is preferred because the student will be exposed to the natural consequence of the behavior immediately; as the last step is taught first. Instruction of the steps will always conclude with access to the natural consequence of the replacement behavior.

5 Prompting is another instructional method for teaching replacement behaviors. Prompting can be used in isolation when teaching the steps of the task analysis, or can be incorporated when using a chaining strategy or discrete trial training. Prompting involves providing cues (verbal, tactile, visual, gestural, and physical) to signal for the student to provide a response. The goal of a prompting strategy is to fade teacher assistance as the student becomes more fluent in performing the replacement behavior and can use natural cues to signal the response. Finally, replacement behaviors can be taught using a shaping strategy. Shaping involves moving the student toward the desired replacement behavior by reinforcing behaviors that resemble the target behavior. The behaviors that resemble the target behavior are called successive approximations. The student may take a long time to learn the target behavior when using a shaping strategy. Once the behaviors have been taught to the student, the effectiveness of the intervention and the support required by the student can be assessed using the frequency, latency, duration, rate, interval, etc. data sheets. Results of the intervention should be graphed to provide a visual record.