Changing Criterion Design
Also known as: Changing-Criterion Single-Case Design, Stepwise Criterion Design, Shaping-Verification Design, CCD
The changing criterion design (CCD) is a single-case experimental method in which a behavior is gradually shaped toward a terminal goal through a series of stepwise performance criteria. Instead of expecting a behavior to leap from baseline to its final target, the analyst sets an initial subgoal, reinforces performance that meets it, and then ratchets the criterion up (or down) once behavior stabilizes at each step. Experimental control is demonstrated when the behavior repeatedly and closely tracks each successive criterion change — changing only when, and to the degree that, the criterion changes — so that each new step functions as another demonstration of effect. The design is especially well suited to behaviors that should change incrementally, such as increasing exercise tolerance, reducing cigarettes smoked, or building a new skill in graded approximations. It belongs to the single-case design family codified by Kratochwill and colleagues in 2013, sharing their requirements for systematic manipulation and replicated demonstrations of effect.
Key highlights
- Demonstrates experimental control while shaping a behavior gradually toward a goal, matching how many skills and habits actually change.
- Avoids withdrawing or reversing an effective intervention to a harmful baseline, since control is shown through criterion tracking.
- Each successive criterion the behavior follows provides another demonstration of effect, building the three-demonstrations evidence base.
- An optional bidirectional criterion change strengthens causal inference by ruling out a simple maturation or trend explanation.
Intuition
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How it works
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When to use it
Use the changing criterion design when the target behavior is best changed gradually and already exists in the individual's repertoire, so that it can be shaped upward or downward in steps rather than introduced wholesale. It fits goals like increasing exercise duration, academic productivity, or social initiations, and reducing behaviors such as smoking or caloric intake, where a stepwise approach is natural and where a return-to-baseline reversal would be undesirable or unethical. The design requires a behavior that can be measured repeatedly and that responds to a contingency tied to a performance criterion, and it assumes the behavior can hold at each step long enough to establish stability before advancing. It is a poor choice for behaviors that change all-at-once, that cannot plausibly be partitioned into graded levels, or that drift so much that tracking of a specific criterion cannot be discerned.
Strengths & limitations
- Demonstrates experimental control while shaping a behavior gradually toward a goal, matching how many skills and habits actually change.
- Avoids withdrawing or reversing an effective intervention to a harmful baseline, since control is shown through criterion tracking.
- Each successive criterion the behavior follows provides another demonstration of effect, building the three-demonstrations evidence base.
- An optional bidirectional criterion change strengthens causal inference by ruling out a simple maturation or trend explanation.
- Works only for behaviors already in the repertoire that can be incrementally raised or lowered, not for newly acquired skills.
- Difficult to interpret when the behavior changes gradually and continuously rather than stepping cleanly with each criterion.
- Choosing step sizes and subphase lengths is judgment-laden; poor choices weaken or obscure the demonstration of control.
- If behavior overshoots or fails to plateau at each step, the close criterion tracking that the design relies on is lost.
Common pitfalls
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Applications
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Frequently asked
How does a changing criterion design demonstrate experimental control?
It shows control through criterion tracking. The behavior is reinforced for meeting a stated performance criterion, and once it stabilizes at that level the criterion is stepped to a new value. If the behavior repeatedly changes to match each new criterion — and only when the criterion changes — it becomes implausible that anything other than the contingency is driving it. Each successive criterion the behavior follows acts as another demonstration of effect, satisfying the single-case standards' requirement for at least three demonstrations within the study.
What is a bidirectional criterion change and why use it?
A bidirectional criterion change temporarily reverses the direction of the criterion — for example, lowering a target the behavior had been climbing toward — to test whether the behavior follows it down as well as up. If the behavior tracks the reversal and then resumes when the criterion is raised again, this rules out the alternative explanation that the behavior was simply improving on its own through maturation or a monotonic trend. The bidirectional check is optional but greatly strengthens the causal claim of the changing criterion design.
When is a changing criterion design preferable to a reversal design?
It is preferable when the behavior should change gradually and when returning it to baseline would be undesirable or unethical — for instance, you would not want to reverse gains in exercise tolerance or reductions in smoking. The changing criterion design demonstrates control without a harmful reversal, by showing the behavior tracks a staircase of criteria. A reversal design is better when the behavior can ethically return toward baseline and you want to isolate a single intervention's on-off effect rather than shape behavior incrementally.
Sources
- 1.Kratochwill, T. R., Hitchcock, J. H., Horner, R. H., Levin, J. R., Odom, S. L., Rindskopf, D. M., & Shadish, W. R. (2013). Single-case intervention research design standards. Remedial and Special Education, 34(1), 26-38.
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Cite this page
ScholarGate. (2026, June 23). Changing Criterion Design. ScholarGate. https://scholargate.app/disability-studies/changing-criterion-design