Uncorrected Tau single-case calculation compares every baseline observation with every intervention observation. Score each pair as improvement, deterioration, or tie in a predefined direction. Subtract deterioration pairs from improvement pairs and divide by all pairs, including ties. Report the signed result, pair counts, phase sizes, raw graph, and the fact that this version does not correct baseline trend.

Create all cross-phase pairs

Pair every valid baseline value with every valid intervention value. The denominator equals the product of phase sizes. Keep dates and values beside pair IDs so a correction to one source point can be traced through every affected comparison.

Set improvement direction before scoring

Write whether higher or lower values represent the client-selected or clinically meaningful improvement. Score each pair using that direction. A positive sign has no stable meaning when direction is changed after the calculation.

Score improvements, deteriorations, and ties

An intervention value better than its baseline partner is positive, a worse value is negative, and an equal value is tied. Keep the three counts separate. This makes the numerator and denominator auditable.

Calculate the signed coefficient

Use (improvement pairs minus deterioration pairs) divided by all pairs for the uncorrected version described here. Ties contribute zero to the numerator and remain in the denominator.

Name the exact Tau variant

Report uncorrected A-versus-B Tau. Do not imply that baseline trend, intervention trend, statistical uncertainty, or a different Tau-U specification was included when it was not.

Build Sana's cross-phase pair ledger

Start with a locked worklist for Sana. Record the review question, metric name, formula version, phase labels, improvement direction, planned and valid observations, missing or invalid states, tie handling, trend handling, source timestamps, calculation owner, and review date. The uncorrected Tau result should be reproducible from this worklist without relying on an unlabeled dashboard value. Keep the data in their original unit so reviewers can connect the supplement to the graph and to the actual outcome. For the uncorrected Tau single-case calculation question, Sana's reviewer also records the release criterion, expected evidence, unresolved limitations, and exact action that the result may inform. This small decision log prevents a calculation from becoming an open-ended label and lets a later reviewer distinguish the observed value from the judgment made with it.

Work the calculation for Sana

Sana's baseline values are 2, 4, and 6; intervention values are 3, 5, 6, and 8; higher values represent improvement. The 12 cross-phase pairs contain 8 improvements, 3 deteriorations, and 1 tie. Uncorrected Tau is (8 minus 3) divided by 12, or 0.417. The positive sign reflects the declared direction. Show every intermediate count or statistic at enough precision to reproduce the displayed result. Keep the raw phase values in chronological order beside any sorted, paired, or transformed table. The fictional arithmetic illustrates the method; it does not create a clinical threshold, minimum phase size, or promised treatment effect.

Audit Sana's denominator and formula

Sana's ledger confirms 3 baseline points times 4 intervention points equals 12 pairs. It reconciles 8 + 3 + 1 to 12, records the tied 6 versus 6 pair, and preserves every pair score. A second reviewer can reproduce the signed numerator of 5 without consulting a hidden calculator. The audit also checks duplicate timestamps, silent imputation, phase-boundary drift, direction reversal, premature rounding, spreadsheet ranges, software version, and correction history. Any unresolved source discrepancy stays on hold with an owner and due date instead of being converted into a convenient zero or exclusion.

Watch for the main failure mode in Sana's review

A frequent error drops ties from the denominator or converts a deterioration into improvement after the desired direction changes. Another error calls the result Tau-U while omitting which trend components were included. Sana's worksheet prevents both by naming the version uncorrected A-versus-B Tau and locking direction before pair scoring. Reviewers should be able to see how one point, tie, extreme, missing observation, or phase-length decision affects the result. A sensitivity example is labeled as hypothetical and never mixed with observed evidence.

Integrate the metric with visual and design analysis for Sana

The next step is to compare the pair result with level, trend, variability, overlap, immediacy, and repeated demonstrations on the graph. If baseline already improves in the same direction, Sana's team follows a predeclared trend-review rule rather than quietly altering the calculation after seeing 0.417. The WWC Version 5.0 handbook is a research evidence standard, so its design criteria are not a universal clinical protocol. In care, the responsible clinician also considers current assessment evidence, professional scope, the treatment plan, ordinary supports, risk, and the person's choices.

Protect client relevance and access for Sana

During Sana's ranked separation between baseline and intervention review, keep augmentative and alternative communication, interpreters, mobility, food, water, bathroom use, prescribed care, health support, rest, relationships, and emergency help available. Use accessible communication to ask whether the goal, direction, magnitude, burden, and observed change matter to Sana. A favorable coefficient cannot repair an unwanted target, inaccessible measurement process, unsafe plan, or missing consent and assent process.

Use current evidence within scope for Sana

For Sana's uncorrected Tau review, the BACB ethics hub and CASP public summary provide professional context, while the BCBA Test Content Outline supplies examination scope for measurement, graphing, interpretation, experimental design, and data-based evaluation. A single-case methods review describes common overlap, Tau, and two-SD calculations. Decision-accuracy research shows why phase size and design structure matter and why overlap percentages do not measure distance. A reproducibility tutorial documents ambiguity among Tau-U implementations and baseline corrections. Nonoverlap and mean-difference methods explain their distinct information targets. ASHA supports continuous access to AAC tools or devices.

Close Sana's supplemental analysis review

Review the cross-phase pair ledger with Sana and the responsible qualified clinician. Preserve source data, graph, phase definitions, calculation specification, coverage, ties, uncertainty, limitations, client input, selected action, owner, and next review date. Reopen the analysis when the measure, phase, context, access, health, goal, software, or design changes. The final note should make clear which conclusions are supported, which remain uncertain, and which require different evidence.

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