ABA graph data paths should follow a written convention for phase boundaries, missing observations, long gaps, and measurement changes. Connecting points suggests continuity between observed values. Break or separate the path when the intervening condition, unit, definition, or series changes enough to make that implication misleading. Keep every source point available regardless of the chosen display convention.

Define the connection rule

State when adjacent observations connect within a condition and when the path breaks.

Separate phase conditions

Use phase lines, labels, and distinct paths when a condition change is material.

Mark missing and invalid observations

Show the state and reason while withholding a data point for an unavailable outcome.

Restart after measurement changes

Create a separate series if unit, response definition, or denominator changed.

Write the path rule before plotting

Define how the graph treats adjacent valid observations, phase boundaries, invalid points, cancelled sessions, long calendar gaps, and changes in measurement. Store the rule with the graph version. Applying one convention across the review period prevents a path from being connected or broken simply because one choice produces a more persuasive picture.

Use a separate state for a missing observation and a measured zero. A true zero receives a plotted point. A missed or invalid observation receives a gap, annotation, or missing-state marker. Preserve the reason and source in the data table.

Reconcile Quinn's sequence

Quinn has five baseline points and five valid treatment points, with one invalid observation between the third and fourth valid treatment points. Draw the baseline path only among the five baseline observations. Start a new treatment path after the phase boundary. Mark the invalid treatment observation at its position without assigning it a value.

Whether the two later valid points reconnect to the earlier treatment path depends on the written convention and the question. A resumed path can communicate that the same treatment condition continued, while a visible break emphasizes unavailable data. In either case, the caption should state that no outcome was measured for the invalid observation.

Break paths when comparability changes

Start a new series when the response definition, unit, denominator rule, or scale changes materially. Also consider a break when a setting, access support, or procedure changes enough that visual continuity would imply a common condition. Add a transition note when the boundary remains uncertain.

A connected line links observed values. It does not measure what happened between them and does not establish that the phase caused a later change. Keep those interpretation limits visible in clinical review.

Review ABA graph data paths before release

The data-path convention sheet for Quinn identifies the clinical question, source record, unit, denominator, time basis, display rule, qualified decision owner, and next review before construction. Preserve the raw data and the exact graph version shown to reviewers.

Work the graph example for Quinn

Quinn has five baseline points, a phase change, three treatment points, one invalid observation, and two later valid points. The graph separates baseline from treatment, leaves the invalid observation as a labeled gap, and resumes the treatment series after the gap without inventing a value.

Audit what the display leaves out for Quinn

For Quinn, record missing observations, invalid points, small or zero denominators, phase uncertainty, context changes, access conditions, and any series hidden by aggregation. A clean picture gains value only when those states remain available for review.

Protect access and client meaning for Quinn

During Quinn's honest graph continuity review, keep AAC, interpreters, mobility, food, water, bathroom use, prescribed care, health supports, rest, relationships, and emergency help available. Ask the person through accessible communication whether the outcome and display reflect something useful. Immediate safety action never waits for graph completion.

Use sources within their role for Quinn

For Quinn, the BACB ethics hub and CASP public summary provide professional context. The BCBA Test Content Outline includes graphing, visual analysis, and data-based decisions as examination content. The WWC handbook page and Version 5.0 handbook address research review, so routine care should avoid borrowing a causal claim without suitable design.

For the honest graph continuity question, Lobo and colleagues discuss single-case design and analysis, while Wolfe, Barton, and Meadan describe systematic visual-analysis protocols. McTiernan and colleagues show that linear and ratio scales can produce different visual impressions. Zonneveld and colleagues study graph-construction training. ASHA supports continuous access to AAC tools.

Close the graph review for Quinn

Review the data-path convention sheet with Quinn and the responsible clinician. Record the display choice, source lineage, graph version, interpretation limits, decision, owner, next data requirement, and review date. Reopen the audit when the definition, measure, axis, condition, criterion, context, access, or software changes.

Before release, check every segment against the path rule, verify phase boundaries and missing states, and confirm that measurement changes start a clearly labeled series. The source table should retain all plotted, missing, invalid, and excluded observations.

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