Single-case nonoverlap without replication can show a striking difference between one baseline and one intervention phase, yet it does not by itself establish a functional relation. One AB transition remains vulnerable to history, maturation, measurement change, and other coincident events. Report the separation, original-unit magnitude, timing, and client relevance, then state which planned replications or stronger design features are absent.

Report the observed separation

Show phase ranges, overlapping count, denominator, original-unit difference, and graph rather than relying on the phrase complete nonoverlap.

Count basic effects

State that one AB boundary provides one phase comparison even when many points fall on each side.

List coincident alternatives

Review history, schedule, staffing, measurement, health, access, maturation, and other changes at the transition.

Describe missing replication

Name the safe and feasible design opportunities that were absent rather than implying a complete experiment.

Preserve clinical meaning

Ask whether Owen values the change, whether it lasts, and whether any cost or side effect matters alongside the design limit.

Build Owen's nonoverlap-without-replication review

For the single-case nonoverlap without replication question, create a versioned nonoverlap-without-replication review. Preserve the target definition, unit, opportunity or observation time, raw series, graph, phase boundaries, design logic, predicted changes, planned demonstrations, actual implementation, measurement quality, client input, access and safety evidence, context, reviewer judgments, and claim status. The record should let another qualified reviewer reconstruct Owen's evidence without relying on a summary score.

Work through Owen's replication example

Owen's baseline values are 1, 2, 1, and 2, while intervention values are 8, 9, 8, and 9. No intervention value overlaps the baseline range, and the median increases from 1.5 to 8.5. The pattern is large and immediate, but it occurs at one transition and supplies one basic effect. Display every value, phase, denominator, and time sequence. This fictional clinic cooperative-play study example illustrates one evidence pattern and does not establish a universal phase length, effect threshold, functional relation, treatment recommendation, or review outcome.

Audit Owen's design evidence

Owen's review verifies the raw series, equal observation time, unchanged definition, implementation date, setting events, and graph scale. It reports zero of four intervention values within the baseline range and labels replication absent. The audit also checks graph axes, session spacing, invalid and missing states, implementation fidelity, condition discriminability, carryover, definition changes, concurrent events, software settings, and correction history. A missing field does not become a negative value or disappear from the denominator.

Address Owen's main inference risk

A metric can return 100 percent separation from short phases. That result describes the observed phases, not the probability of causation, generalization, durability, or benefit. Owen's report keeps those questions separate. Reviewers describe the raw pattern first, then the narrower conclusion it supports. A clinical improvement can be real and valuable even when the design cannot attribute it confidently, and a strong experimental contrast can still lack personal importance.

Decide the next evidence step for Owen

A stronger design might add safe reversal, staggered replication, repeated condition comparisons, or another prospective demonstration. The choice depends on the question, welfare, feasibility, and expected carryover. The responsible clinician and methodologist choose any added observation, replication, design change, or claim revision. The choice protects needed care, uses prospectively stated rules where possible, and preserves the original graph and decision history.

Protect Owen's access and participation

Keep Owen's augmentative and alternative communication, interpreters, mobility, food, water, bathroom use, prescribed care, health support, rest, relationships, and emergency help available throughout the clinic cooperative-play study. Use accessible consent and assent processes when applicable and respond to withdrawal, dissent, or distress. A replication plan never supplies authority to withhold a necessary support or delay urgent action.

Apply current sources to Owen's review

Owen's source set treats nonoverlap as one visual feature and replication as a separate requirement for stronger causal inference. The BACB ethics hub and CASP public summary provide professional context, while the BCBA Test Content Outline identifies examination content on measurement and single-case design. The WWC Version 5.0 handbook supplies a current research-review framework. A single-case design review, systematic visual-analysis protocols, current analytic reflections, nonconcurrent multiple-baseline methods research, and a visual-analysis software tutorial describe methods and limits. ASHA supports continuous AAC access.

Rehearse Owen's review process

Before live use, run the nonoverlap-without-replication review on fictional graphs with a strong effect, weak effect, delayed effect, opposite trend, carryover, missing agreement, one contradictory tier, and no replication. Confirm that reviewers preserve raw values, count planned opportunities separately from observed demonstrations, identify holds, and keep client relevance distinct from causal inference. Store test cases, expected decisions, software version, and correction log.

Close Owen's claim review

Review the nonoverlap-without-replication review with Owen, the responsible clinician, and a methodologist familiar with the exact design. Preserve raw data, graph, design protocol, basic effects, demonstrations, fidelity, measurement checks, contextual events, client input, reviewer disagreements, source standard, final wording, and limits. Keep the page draft and noindex until all manifest-named reviews are complete.

Related resources

Sources