To compare ABA data when opportunity density changes, report eligible opportunities per time alongside response count and responses per opportunity. Separate the client's performance from the environment's opportunity supply. Record partner, schedule, task, access, and setting changes. A higher response count can occur with lower opportunity performance, while a stable count can mask improved performance under fewer opportunities.

Measure the opportunity supply

Count eligible cues or chances per time and identify who or what creates them.

Keep client and partner behavior separate

Report Faye's response, partner recognition, and requested outcome as different measures.

Track environmental change

Record schedule, task, staffing, access, materials, and setting changes that alter opportunity availability.

Avoid count-only claims

State whether count, time rate, opportunity rate, or meaningful outcome changed. Each supports a different conclusion.

Hold definitions and exposure steady

Before comparing periods, verify that "eligible opportunity" and "response" mean the same thing, the observation windows are known, and ordinary supports remain documented. If one period lasted longer, convert opportunities and responses to the same time unit. If the schedule redesign changed which situations qualified as opportunities, label that definition change and avoid treating the two opportunity percentages as a clean repeated measure.

Use the formula and its units for Faye

For Faye's opportunity-density change review: opportunity density = eligible opportunities / observed time; opportunity performance = responses / eligible opportunities. Write the unit beside every result and keep the original numerator, denominator, time, opportunities, response definition, and condition. State rounding only after the unrounded calculation is preserved.

Work the arithmetic for Faye

During the first observed hour, Faye has four eligible opportunities and responds in three. Opportunity density is 4/1 = 4 opportunities per hour, response rate is 3/1 = 3 responses per hour, and opportunity performance is 3/4 = 75%.

During a one-hour observation after schedule redesign, she has ten eligible opportunities and responds in six. Opportunity density is 10 opportunities per hour, response rate is 6 responses per hour, and opportunity performance is 6/10 = 60%. The opportunity supply is 2.5 times the earlier rate, the response count and time rate double, and performance per opportunity decreases by 15 percentage points. Each statement is arithmetically correct and answers a different question.

Interpret the three-part pattern

The redesign appears to create more chances for the response, but the data alone do not establish why performance per opportunity is lower. The team reviews whether opportunities were equally detectable, useful, and accessible, whether partners waited and honored the response, and whether the higher density created fatigue or burden. Faye's view of the schedule and the meaningful outcome of her questions belong beside the counts.

If a valid one-hour observation contains zero eligible opportunities, opportunity density is 0/1 = 0 opportunities per hour, while response performance per opportunity is undefined because its denominator is zero. If eligible opportunities occurred but Faye made zero responses, the performance result is a true 0 divided by the positive opportunity count. If observed time is missing or invalid, the team cannot calculate opportunity density. These states stay separate in the table and graph.

A useful graph can place opportunity density and response rate in separate panels with the same time axis, then show opportunity performance with its numerator and denominator. Avoid one dual-axis line that makes unlike units look directly comparable. A concise report states all three changes and names the schedule redesign without claiming it caused them.

Apply opportunity-density evidence to a decision

Faye's qualified clinician identifies the decision before selecting the summary or display. Compare at least one alternative unit or classification, inspect client access and direct experience, and record what evidence would change the interpretation. A correct calculation can still answer the wrong question.

Audit data states for Faye

Faye's record distinguishes valid observed values, true zeros, missing observations, invalid events, no opportunities, not-due records, late entries, corrections, and incompatible conditions. Give unresolved items an owner, age, and next action. Preserve the original evidence and the reason for every exclusion or change.

Protect access and context for Faye

Faye's measurement keeps AAC, interpreters, mobility, food, water, bathroom use, prescribed care, health support, rest, relationships, and emergency help available. Record ordinary supports, partner response, setting, schedule, burden, and withdrawal. The data system should describe care without creating unsafe or inaccessible test conditions.

Ask five calculation questions for Faye

Use these questions in the opportunity-density change review:

  • What exact response, event, opportunity, time exposure, unit, and condition does the value represent?
  • Which raw numerator, denominator, clock, source, and calculation reproduce it?
  • Which zero, missing, invalid, not-due, corrected, censored, or incompatible states stay separate?
  • Which client experience, access, integrity, agreement, burden, and context qualify interpretation?
  • Which clinical decision, alternative display, next evidence, owner, and review date follow?

Keep raw counts and units beside every derived value.

Use current sources within their scope for Faye

For Faye's opportunity-density change review, the BCBA Test Content Outline includes measurement, validity, reliability, sampling, graphing, assessment, and data-based decisions as examination content. It is not a case protocol. The BACB Ethics Code addresses competence, client involvement, consent and assent when applicable, documentation, risk, and evaluation for covered behavior analysts. The CASP public summary supplies high-level autism-treatment scope without publishing licensed detailed procedures.

For Faye, ASHA says AAC users should always have access to their communication tools or devices. The WWC Version 5.0 handbook supplies research-review standards, not universal clinical formulas, thresholds, or decision rules. None of these sources turns a derived metric into proof of effectiveness, safety, medical necessity, compliance, or causation.

Close Faye's measurement review

Ask Faye and the responsible clinician to review the opportunity-density change review through accessible communication. Record the raw data, calculation, unit, display, assumptions, missingness, context, interpretation limits, selected decision, next evidence, and review date. Reopen the analysis when the response definition, exposure, opportunity, setting, measurement system, client priority, or access changes.

Related resources

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