Welcome to Seminar! PS 512 Unit 2 Any questions to start??

Issues in Single Subject Research Prediction Verification Replication Reliability Validity Ethics

We use single subject research to determine functional relationships between variables in Applied Behavior Analysis As in any experimental design, we manipulate the Independent Variable and measure the dependent variable. Independent Variable=Intervention Dependent Variable= Target Behavior We measure behavioral and environmental events, apply interventions, then determine whether there is any change due to our interventions

It is essential that we: Define and measure independent and dependent variables with precision Control manipulation of the independent variable and measurement of the dependent variable and, Identify and Control outside factors that may be influencing our variables of interest

Example Use of A DRO Procedure for Reducing Disruptive Outbursts in the Classroom – Independent Variable: Use of positive reinforcement Definition: When the student is in seat and quiet, the teacher will give praise and a token every 5 minutes. – Dependent Variable: Not Disruptive Definition: Student is in seat and quiet

Procedure Measure Baseline Apply Intervention Measure Change

Prediction: If there is no effect attributable to the independent variable (intervention), the dependent variable’s data path will remain the same Verification: Confirmation that the dependent variable is changing in a predictable fashion Replication: Repeating of the observed predictions and verifications within the same study

Frequency of disruptions Day Baseline Praise Baseline A B A

Validity Internal Validity : Degree to which the researcher has adequately controlled the independent, dependent, and extraneous variables – Extraneous Variables: Anything outside the study that may be affecting the results – Confounding Variables

Threats to Internal Validity History – Passage of time and effect of external events over time Maturation – Natural development of an individual over time Attrition – Loss of subjects during a study Multiple Treatment Interference – Effects caused by use of more than one intervention Treatment Drift – Individuals responsible for administering interventions making changes to procedures

External Validity External Validity: Degree to which other researchers are likely to achieve the same results with other individuals, other target behaviors, or in other settings. External Validity is demonstrated through Direct and Systematic Replication:

Direct Replication – Attempts to duplicate the procedures as closely as possible Systematic Replication – Varying conditions from earlier studies, but achieving similar results

Ethics Single subject designs incorporate very powerful means for changing behavior, and Are often used to treat people in vulnerable populations – People with DD – Children, etc. Review Guidelines on Page 99 of your text Review BACB.com Guidelines for Responsible Conduct

PS 512 Looking Ahead to Unit 3 Withdrawal Designs

Readings: Chapter 5, Chapter 6 Schilling, D., & Schwartz, I. (2004). Alternative Seating for Young Children with Autism Spectrum Disorder: Effects on Classroom Behavior. Journal of Autism and Developmental Disorders, August, Vol. 34(4), p Retrieved from ERIC Database.

Basic Withdrawal Designs Withdrawal designs provide direct evidence for Prediction, Verification, and Replication AB Baseline / Treatment ABA Baseline/ Treatment / Baseline ABAB Baseline/ Treatment/ Baseline/ Treatment Of these designs, the ABAB is the most useful for demonstrating functional relationships

Withdrawal Designs Video

Withdrawal designs are useful : – For demonstrating clear functional relationships between variables – When the intervention can be reversed – When the effects of the intervention will not remain once the treatment is reversed – When withdrawal of treatment does not compromise ethics

Example The effect of praise on increasing ‘In Seat’ behavior First Steps: – Define ‘In Seat’ – Define ‘Praise’ Baseline (A)Treatment (B)Baseline (A)Treatment (B) Measure ‘in seat’ behavior for 3 days under current conditions Praise every 2 minutes when ‘in seat’ for 5 days Discontinue praise for 3 days Praise every 2 minutes when ‘in seat’ for 5 days. Continue treatment if effectiveness is demonstrated

Withdrawal designs are less useful: – When the target behavior is not reversible – When the treatment effects continue after the treatment is withdrawn – When it’s not in the client’s best interest to return to baseline – When withdrawal of treatment would be unethical

Examples Using Physical Prompting and Differential Reinforcement to decrease self injurious face slapping Problem: It may be dangerous or unethical to withhold treatment while collecting baseline data or in a reversal phase Aversive treatment to eliminate ‘alcohol drinking’ behavior Problem: Effects of aversive therapy are likely to linger beyond the treatment period

Variations of the Basic Withdrawal Design BAB Treatment/ Baseline/ Treatment – When impossible or inappropriate to take an extended baseline ABABAB Base/Treat/Base/Treat/Base/Treat – To increase confidence in the functionality of the relationship we’ve demonstrated ABC Baseline/Treat 1/Treat 2 – When trialing different treatments ABAC Base/Treat 1/Base/Treat 2 – When trying to increase experimental control while trialing different treatments

Use Physical Prompting and Differential Reinforcement to decrease self injurious face slapping TREATMENTBASELINETREATMENT Implement intervention procedure for 10 days Brief withdrawalImplement intervention procedure and continue if effective

Using Token Reinforcement to increase percentage of time spent “In Seat” ABAB BaselineInterventionBaselineIntervention Measure amount of time spent in seat for 5 days Reward with tokens on pre described schedule of reinforcement for 10 days Discontinue tokens for 3 days Reinstate tokens

ABAC Using Praise, then Token to Increase % Time in Seat BaselineTreatment(Praise)ReversalTreatment(Tokens) Measure time in seat for 5 days Reward with praise on pre determined schedule 5 days Discontinue praise for 3 days Reward with tokens for 5days

Down load this ppt and run as slide show to view embedded videos Graphing Single Subject Reversal Design with Excel Graphing Single Subject Reversal Design with Excel

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