Which pairing of a single-subject design with its described strength is correct?

Which pairing of a single-subject design with its described strength is correct?

• A. AB Design — Demonstrates Functional Relation
• B. ABAB Reversal — Demonstrates Functional Relation
• C. Multiple Baseline Across Settings/Tasks — Simple Baseline Control
• D. Changing Criterion — Ethical Alternative to Reversal

Answer: (B)

The key idea is showing that the intervention actually causes the behavior change, not other factors. In an ABAB reversal, you introduce the treatment, withdraw it, and then reintroduce it. If the target behavior decreases when the treatment is removed and increases again when it’s brought back, you get a clear pattern that the treatment is controlling the behavior. This replication across phases provides strong evidence of a functional relation between the intervention and the behavior. The other options don’t fit this strongest criterion. An AB design lacks a second reversal, so you can’t rule out confounds because you don’t show the behavior returning to baseline and then changing again with reintroduction. Across-settings/tasks in a multiple baseline design demonstrate generalization and control across contexts, not a simple baseline control. Changing Criterion shows gradual, stepwise changes in behavior as the reinforcement criteria shift, not an ethical alternative to reversal.

The key idea is showing that the intervention actually causes the behavior change, not other factors. In an ABAB reversal, you introduce the treatment, withdraw it, and then reintroduce it. If the target behavior decreases when the treatment is removed and increases again when it’s brought back, you get a clear pattern that the treatment is controlling the behavior. This replication across phases provides strong evidence of a functional relation between the intervention and the behavior.

The other options don’t fit this strongest criterion. An AB design lacks a second reversal, so you can’t rule out confounds because you don’t show the behavior returning to baseline and then changing again with reintroduction. Across-settings/tasks in a multiple baseline design demonstrate generalization and control across contexts, not a simple baseline control. Changing Criterion shows gradual, stepwise changes in behavior as the reinforcement criteria shift, not an ethical alternative to reversal.