This document discusses key aspects of single-subject research designs, including ABAB and multiple baseline designs. ABAB designs involve measuring a target behavior across baseline and intervention phases, allowing for inferences about causality. Multiple baseline designs demonstrate causality by applying an intervention to different targets, participants, or settings only when behavior changes, establishing the intervention as the cause. Both designs require stable baselines, marked changes during interventions, and replication to demonstrate internal and external validity.

1. #8 Location In The Research Process Formulating Research Questions Previous Research Craft Knowledge Appropriate Design Appropriate Sampling Decisions Ensure Research Ethics Data Collection & Management Data Analysis Interpretation Dissemination Ongoing Research

2. Basic Requirements Of All Single Subject Designs Continuous Assessment Several observations of the target behavior Across all phases of the study A minimum of three times during each phase Baseline Assessment Of Functioning Data about what expected performance would be Descriptive function (control phase) Predictive function Baseline Data Should Be Stable Without trend and have little variability

3. Internal and External Validity Internal Validity The extent to which alternate explanations, beyond the variable of interest, can be ruled out External Validity The extent to which results of an experiment can be generalized beyond the conditions of an experiment

4. Internal and External Validity Internal validity addressed through Withdrawal or reversal with repeating phases Comparing across multiple baselines External validity addressed through replication At least four cases per study

5. Two Types of Experimental Single Subject Designs AB designs are pre-experimental Establishing measurement accuracy Detecting preliminary data trends Cannot infer causality ABAB Designs Are Experimental Withdrawal and Reversal take place Multiple Baseline Designs Are Experimental Target behavior changes when and only when an intervention is applied to that behavior

6. A first baseline phase describes and predicts the target First intervention phase, when the intervention is applied and the target is measured Next comes a second baseline phase, also known as a withdrawal phase, when the intervention is removed and the target is measured Finishes with a second intervention phase, maintained as long as is needed, and then faded out ABAB Design - Implementing

7. A stable first baseline phase a marked change during the first intervention phase A clear return to first baseline performance levels during the second baseline phase Another marked change in the target during the second intervention phase ABAB Design - Analyzing

8. ABAB Design - Analyzing

9. Phases can be ordered differently within ABAB designs As long as there are at least two intervention phases and two baseline phases Intervention and baseline phases are adjacent to each other Treatment comparisons can be made An ABCABC design for example The ordering of treatments should be changed across replications ABAB Design - Considerations

10. Problems with ABAB designs Absence of reversal The target doesn't return to first baseline levels during the second baseline phase Undesirability of reversing behavior In some instances it is unethical to allow the client to worsen, even for a brief period of time Especially if the behavior has a risk of harming anyone

11. Multiple Baseline Designs Test causality Demonstrating that a target behavior changes when and only when an intervention is applied to that behavior Require highly specified targets and interventions

12. Multiple Baseline Designs Can Be Implemented Across behaviors At least three different target behaviors Across participants With a single intervention being compared across at least three participants who have the same target Across settings with a single intervention being applied to a single participant across at least three different settings Across Change Agents

13. Collect baseline data On at least three targets, participants, or settings/change agents Apply an intervention To only one target, participant or setting After change is demonstrated in the first target, participant or setting Apply an intervention to another single target, participant or setting After change is demonstrated in the second target, participant or setting Apply an intervention to another single target, participant or setting Multiple Baseline - Implementing

14. Multiple Baseline Design - Analyzing

15. Problems With Multiple Baseline Designs Interdependent baselines When behaviors change before the intervention is applied to them Inconsistent intervention effects Add ambiguity to conclusions about interventions Prolonged baselines Raise clinical and ethical issues Raise the risk that a behavior may change before an intervention is applied