To calculate scored interval IOA, divide intervals in which both observers scored occurrence by intervals in which either observer scored occurrence, then multiply by 100. The method focuses on agreement when behavior was recorded and can be useful for low-frequency events. Report event prevalence, matched exposure, and overall disagreement because the method ignores joint-nonoccurrence intervals.

Define occurrence

Specify the response form, interval rule, AAC access, prompt boundary, and observation visibility.

Build the occurrence denominator

Include every interval in which Observer A, Observer B, or both scored occurrence.

Count joint occurrence

The numerator contains only intervals where both observers scored occurrence.

Report complementary context

Show total intervals, occurrence prevalence, disagreements, and another agreement view when the decision needs it.

Reconcile the binary interval table

Store four cells for every matched valid interval: both observers record occurrence, both record nonoccurrence, Observer A only records occurrence, and Observer B only records occurrence. The cells must sum to the full matched-interval denominator. Intervals observed by only one person remain in coverage and stay outside the IOA calculation.

For Noor, four joint-occurrence intervals plus two disagreements create the six-interval scored denominator. The remaining six are joint nonoccurrences. The complete table therefore contains four joint occurrences, six joint nonoccurrences, and two one-observer disagreements across twelve matched intervals.

Use scored agreement for the occurrence question

Scored-interval IOA removes joint nonoccurrence from its denominator, which can make it more informative when the behavior is rare. Here, the result is 4/6 = 66.7%. Overall interval-by-interval agreement would be (4+6)/12 = 83.3%, and unscored-interval agreement would be 6/(6+2) = 75%.

The three figures are mathematically compatible and answer different questions. Report the one selected for the decision, then show complementary results when prevalence changes the interpretation. Preserve which observer recorded each of the two unmatched occurrences so visibility or definition patterns can be investigated.

Use the formula and units for Noor

For Noor's scored-interval IOA worksheet: scored-interval IOA = intervals both observers scored occurrence / intervals either observer scored occurrence × 100. Keep observer records independent until both are locked. Preserve the matched exposure, raw observations, numerator, denominator, unrounded calculation, and final rounding.

Work the arithmetic for Noor

Noor's observers compare twelve intervals. At least one observer records the message in six intervals, and both record it in four. Scored-interval IOA is 4 / 6 × 100 = 66.7%. The six joint-nonoccurrence intervals do not enter this calculation.

Apply occurrence-focused agreement to the decision

Noor's qualified clinician identifies the decision before choosing an agreement method or threshold. Compare a stricter or complementary method when prevalence, totals, or aggregation could hide relevant disagreement. Repair definitions, visibility, training, sampling, or matching before judging the implementer or client data.

Audit observer and sample conditions for Noor

Noor's record identifies observers, independence, training, recording mode, shared exposure, response definition, procedure version, observation coverage, missing pairs, reactivity, and disagreements. Consent, privacy, recording, employment, supervision, and payer rules remain separate requirements. Keep every open pair visible with an owner and next action.

Protect client access during Noor's observation

Noor's observation keeps AAC, interpreters, mobility, food, water, bathroom use, prescribed care, health support, rest, relationships, and emergency help available. Do not create extra distress or remove ordinary supports to obtain an agreement sample. Record when access, health, withdrawal, or observer presence changes the condition.

Ask five IOA questions for Noor

Use these questions in the scored-interval IOA worksheet:

  • Did both observers independently score the same exposure, unit, definition, and condition?
  • Which calculation, numerator, denominator, prevalence, and rounding reproduce the result?
  • Which disagreements, missing pairs, invalid units, reactivity, or matching problems remain?
  • Which validity, treatment-integrity, client-outcome, experience, and access questions stay separate?
  • Which repair, complementary method, next sample, owner, and review date follow?

Keep raw observer records and disagreement types available.

Use current sources within their scope for Noor

For Noor's scored-interval IOA worksheet, the BACB ethics hub points to current professional ethics materials. The CASP public summary provides high-level autism-treatment scope without licensed detailed procedures. The BACB Ethics Code addresses competence, client involvement, consent and assent when applicable, documentation, risk, supervision, and evaluation for covered behavior analysts. The BCBA Test Content Outline includes measurement, reliability, sampling, and data-based decisions as examination content rather than a case protocol.

For Noor, Vollmer, Sloman, and St. Peter Pipkin discuss practical implications of data reliability and treatment-integrity monitoring. Essig, Rotta, and Poling review IOA and fidelity reporting in an identified ABA research corpus. Reed and Azulay describe a calculation tool and agreement methods. ASHA says AAC users should always have access to their tools or devices. These sources do not create one universal IOA method or threshold.

Close Noor's agreement review

Ask Noor and the responsible clinician to review the scored-interval IOA worksheet through accessible communication. Record the method, arithmetic, sample, disagreements, limits, measurement repair, selected decision, next observation, and review date. Reopen the analysis when the definition, observer, system, exposure, prevalence, client access, procedure, or decision changes.

Clinician release checklist

  • Do the four binary cells reconcile to all twelve matched valid intervals?
  • Can another reviewer reproduce four joint occurrences, six joint nonoccurrences, and two disagreements?
  • Is scored agreement 4/6 = 66.7% labeled as occurrence-focused?
  • Are overall 10/12 = 83.3% and unscored 6/8 = 75% presented only as complementary views?
  • Are observer coverage, event prevalence, access, disagreement direction, and next action documented?

Related resources

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