A basic effect across adjacent single-case phases is a change in the data pattern that occurs in temporal relation to a condition change. Review level, trend, variability, immediacy, and overlap using the raw graph, while checking measurement, implementation, timing, and context. One basic effect is a phase-pair observation. A functional-relation claim generally requires replicated demonstrations within the appropriate design.

Define the phase pair

Name the conditions, start and end observations, expected direction, measurement unit, and reason the two phases are meaningfully comparable.

Review all visual features

Describe level, trend, variability, immediacy, overlap, and consistency with similar phases rather than allowing one summary to dominate.

Check temporal alignment

Verify when the independent variable actually changed, when measurement occurred, and whether implementation reached the intended person and setting.

List plausible rival changes

Review staffing, schedule, health, access, task, observer, and measurement changes around the boundary.

Label the evidence correctly

Call one phase comparison a basic effect and reserve stronger language for evidence that meets the design's replication logic.

Build Harper's adjacent-phase comparison sheet

For the basic effect adjacent single-case phases question, create a versioned adjacent-phase comparison sheet. 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 Harper's evidence without relying on a summary score.

Work through Harper's replication example

Harper's equal-length phases contain baseline counts 5, 4, 6, and 5, followed by intervention counts 10, 11, 9, and 10. The median moves from 5 to 10, the ranges are 2 in both phases, the boundary change is immediate, and the phases have no overlapping values. This is one clear adjacent-phase basic effect. Display every value, phase, denominator, and time sequence. This fictional supported-employment task study example illustrates one evidence pattern and does not establish a universal phase length, effect threshold, functional relation, treatment recommendation, or review outcome.

Audit Harper's design evidence

Harper's sheet links the eight values to original records, confirms equal observation time, marks the phase boundary, and records implementation fidelity. It evaluates all six visual features and states that the AB comparison supplies one basic effect rather than a replicated causal demonstration. 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 Harper's main inference risk

A large mean difference can coexist with gradual drift, an equipment change, or a definition revision at the boundary. Harper's sheet keeps those alternatives visible instead of treating phase labels as proof that the intervention caused the pattern. 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 Harper

The design review asks where the same predicted change should recur and whether those replications occur at different, planned times. Harper's preferences and practical outcomes remain part of the interpretation even when the graph looks clear. 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 Harper's access and participation

Keep Harper's augmentative and alternative communication, interpreters, mobility, food, water, bathroom use, prescribed care, health support, rest, relationships, and emergency help available throughout the supported-employment task 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 Harper's review

Harper's source trail supports examining within-phase patterns first and then comparing adjacent phases as one basic effect. 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 Harper's review process

Before live use, run the adjacent-phase comparison sheet 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 Harper's claim review

Review the adjacent-phase comparison sheet with Harper, 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.

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