Applied Behavior Analysis for Teachers Chapter 5: Single-Subject Designs

Chapter Overview Variables and Functional Relations Basic Categories of Designs Single-Subject Designs AB Design Reversal Design Changing Criterion Design Multiple Baseline Design Alternating Treatment Design Changing Condition Design Evaluating Single-Subject Designs Action Research and Single-Subject Design Tools

Dependent and Independent Variables The behavior targeted for change. Independent Variable: The intervention being used to change behavior. Functional Relation: A functional relation is said to exist if the dependent variable systematically changes in the manipulation of the independent variable.

What is the Dependent and Independent Variable? To increase compliance in vocational settings by implementing a token reinforcement system. Use picture prompts with students with severe disabilities to increase instruction-following skills. Students will increase their organizational skills by outlining their daily activities on a schedule checklist for six weeks. The use of graduated guidance will enable the student to eventually feed himself. Increase reading skills by two grade levels following instruction using the “I’m A Better Reader” program in combination with time delay. Implement a response cost system for verbal outburst. Give the puppy a treat when he follows his master’s commands. Marty writes his name in the appropriate space in order to obtain teacher approval. When students correctly complete their homework assignments, they earn free time using the computer. Mrs. Hoffman uses differential reinforcement of incompatible behaviors to increase in seat behaviors.

Single-Subject Designs Identifies the effects of variables on a specific behavior of an individual Require repeated measures of the dependent variable (behavior) Emphasize clinical rather than statistical significance Common Components: Baseline At least one measure of performance under an intervention At least one replication of the intervention within the design

Baseline Measures Serve 2 Functions: (Kazdin, 1982, 1998) 1) Descriptive Function 2) Predictive Function How many baseline data points are required? Typically, at least 5 baseline data points or Baseline Stability If no data point of the baseline varies more than 50% from the mean of the baseline.

Calculating Baseline Stability Session Data Points 1 14 2 10 3 20 4 16 5 11 Step 1: Baseline Mean (14 + 10 + 20 + 16 + 11 = 71/5 = 14.2) Step 2: 50% of mean (14 x .50 = 7) Step 3: Acceptable Range of Data Points (14 + 7 =) (7, 21) Step 4: Baseline is stable because no data point varies more than 50% from the mean.

Trends Pattern in the data which indicates a distinct direction in the performance of the behavior 3 data points in the same direction (Barlow & Hersen, 1984) Increasing trend (ascending) Decreasing trend (descending)

AB Design Baseline Intervention Joe

AB Design: Advantages and Disadvantages Simple to use Cannot be used to make a confident assumption of a functional relation. Does not provide for replication

Reversal Design Referred to as ABAB design Involves the sequential application and withdrawl of an intervention to verify the intervention’s effects on a behavior 4 Phases of Reversal Design: 1) A: Baseline 1 2) B: Intervention 1 3) A: Baseline 2 4) B: Intervention 2 Demonstration of a functional relation

Reversal Design Baseline Intervention Baseline 2 Intervention 2 Meg

Reversal Design: Advantages ABAB design is most desirable of reversal designs because it allows us to see the effects of the independent variable on the natural rate of occurrence of the target behavior Use this design: When a clear functional relation between independent and dependent variable needs to be demonstrated When the nature of the target behavior is such that it can be reversed when the treatment is withdrawn When the nature of the treatment is such that its effects are not present on the target behavior after it is withdrawn When withdrawal of treatment does not compromise ethics

Reversal Design: Disadvantages Do not us this design: When the target behavior is not reversible When the treatment effects will continue after the treatment with withdrawn When it is not educationally or clinically desirable for the behavior to return to baseline levels When the target behavior is such that withdrawal of effective treatment would be unethical

Changing Criterion Design Evaluates the effectiveness of an independent variable by demonstrating that a behavior can be incrementally increased or decreased toward a terminal performance goal 2 Phases: 1) Baseline 2) Intervention Intervention phase divided into subphases – each requiring a closer approximation to the terminal behavior

Changing Criterion Design: Graph Baseline Intervention Joshua

Changing Criterion Design: Advantages and Disadvantages Helpful when working on behaviors that are being shaped Helpful when the terminal goal that is set takes a long time to reach The treatment does not have to be withdrawn to show its requisite functional relation with the target behavior Not appropriate when the behavior must occur immediately It may not be appropriate to “hold back” an individual and his/her behavior change

Multiple Baseline Design Allows for simultaneous analysis of more than one dependent variable Experimentally test the effects of the intervention on: Two or more behaviors with one student in a single setting (multiple baseline across behaviors) Two or more students exhibiting the same behavior in a single setting (multiple baseline across students) Two or more settings in which one student is exhibiting the behavior (multiple baseline across settings)

Multiple Baseline Design: Graph Jim Percentage of Occurrences Pete Jose

Multiple Baseline: Advantages Use this design: When withdrawal designs are not feasible due to ethical concerns When there is more than one target behavior, setting, or individual in need of treatment When the effects of the independent variable cannot be withdrawn or reversed

Multiple Baseline: Disadvantage Do not use this design: When selected target behaviors are not functionally similar nor independent of one another If there is only one individual/setting/behavior selected for treatment When more than on intervention phase is desirable to demonstrate a functional relation When constraints on resources make implementation impossible

Alternating Treatments Design Allows comparison of the effectiveness of more than one treatment or intervention strategy on a single dependent variable Scheduling of interventions should be counterbalanced Fractionation of the data 3 Phases: 1. Baseline 2. Intervention 3. Replication

Alternating Treatments Design: Graph Baseline Intervention Replication Cindy

Alternating Treatment Design: Advantages Use this design: When you want to determine the relative effectiveness of more than one treatment on a given behavior When baseline data are either unavailable or might be unstable When the treatments are sufficiently different from each other When the subjects can discriminate the treatment conditions When the effects of sequencing the interventions might obscure the results

Alternating Treatment Designs: Disadvantages Avoid this design: When the treatments might interact, thus obscuring the results When the subjects cannot discriminate the treatment conditions When the treatments typically produce slow behavior changes When the treatments need to be administered over a continuous period of time to be effective When it becomes difficult to counterbalance the various aspects of the study

Changing Condition Design Used to investigate two or more interventions on a behavior Interventions administered sequentially Variations: ABC ABAC ABACAB

Changing Conditions Design: Graph Baseline Intervention 1 Baseline Intervention 2 Nicole

Changing Conditions Design: Advantages and Disadvantages Used to investigate the effect of two or more treatments on the behavior of a student Cannot be used to determine the effects of a functional relation between the dependent variable and any of the tested independent variables

Evaluating Single-Subject Designs Analysis of Results Experimental Criterion Clinical Criterion Social Validity Mean of data points within a phase Levels of Performance Across Phases Percentage of Overlapping Data Points Rapidity of Behavior Change

Action Research A systematic inquiry conducted by teachers and other education professions in teaching/learning environments to gather information and reflect upon how their school operates, how they teach, or how well their students learn. Components of Action Research: 1) identify an area of focus or concern 2) collect data for documentation 3) analyze and interpret data 4) share the information with other and develop an action plan (Arhar, et al., 2001; Schoen & Nolen, 2004; Stringer, 2004; Mills, 2003)

Key Terms variable enhanced functioning dependent Variable changing criterion design independent variable multiple baseline design baseline data alternating treatment design functional relation changing conditions design trend group designs reversal design single-subject designs ABAB design