BCBA Exam Formulas – Verified Study Guide & Calculations for 2026

BCBA Exam Formulas
Total Count IOA - Smaller #/Larger # x 100%

Mean Count-Per-Interval IOA - Int 1 IOA + Int 2 IOA + Int N IOA/Total # of Intervals
x 100%

Exact Count-Per-Interval IOA - # of Intervals of 100% agreement/total # of Intervals x
100%

Trial-by-Trail IOA - # of Trials of Agreement/Total # of Trials x 100%

Total Duration IOA - Shorter Duration/Longer Duration x 100%

Mean Duration (or IRT)-Per-Occurrence IOA - Duration IOA B1 + Duration IOA B2 +
Duration IOA Bn/n Behaviors with Duration IOA

Interval-By-Interval IOA - # of Intervals Both Recorders Agree/Total # of Intervals x
100%

Scored Interval IOA - # of Intervals Both Recorders Recorded Occurrence/# of Intervals
AT LEAST ONE Recorder Recorded Occurrence x 100%

Unscored Interval IOA - # of Intervals Both Recorders Recorded Non-Occurrence/# of
Intervals AT LEAST ONE Recorder Recorded Non-Occurrence x 100%

For Increasing Behaviors f- fBaseline fAverage f< fInitial fCriterion f</= fHighest fPerformance
fin fBaseline


For fDecreasing fBehaviors f- fBaseline fAverage f> fInitial fCriterion f>/= fLowest
fPerformance fin fBaseline


Setting fInitial fNCR fSchedule f- fTotal fDuration fof fAll fBaseline fSessions/Total f# fof
fBehaviors fRecorded fDuring fBaseline fSessions


Setting fInitial fDRO fInterval f- fTotal fDuration fof fAll fBaseline fSessions/Total f# fof
fBehaviors fRecorded fDuring fBaseline fSessions


Full fSession fDRL f- fTotal f# fof fBehaviors fRecorded fDuring fBaseline fSessions/Total f# fof
fEach fBaseline fSession


Interval f& fSpaced fResponding fDRL f- fTotal fDuration fof fBaseline fSessions/Baseline
fAverage fof fBehaviors fper fBaseline fSessions f= f# fof fBehaviors fper fduration


Conditional fProbabilities f- f# fof fBehaviors fPreceded fby fa fSpecific fAntecedent f&/or
fFollowed fby fa fSpecific fConsequence/Total f# fof fBehaviors f- falways freported fin fdecimal
fform