Occurrence, Rate, Duration, Latency, IRT, Trials to Criterion, and Efficiency
Key Takeaways
- Occurrence data include count and rate, but rate is preferred when observation times differ.
- Duration, latency, and IRT answer different time-based questions.
- Trials to criterion helps compare learning efficiency across targets or procedures.
- Efficiency considers outcomes relative to time, effort, prompts, errors, or resources.
Dimensions and Decision Questions
Occurrence tells whether behavior happened and how often. Count is the raw number of responses. Rate adds time, such as responses per minute, and is usually stronger when sessions are not the same length.
Dimension Guide
| Dimension | Use when the question is... |
|---|---|
| Count | How many responses occurred in equal periods? |
| Rate | How often per unit of time? |
| Duration | How long did behavior last? |
| Latency | How long after the cue until behavior started? |
| IRT | How much time passed between responses? |
| Trials to criterion | How many opportunities were needed for mastery? |
Efficiency is not just speed. It asks whether meaningful behavior change is achieved with acceptable time, effort, errors, prompts, materials, and staff capacity.
For acquisition programs, trials to criterion and rate of independent correct responding often matter more than percent correct on a single day. For reduction programs, rate, duration, latency, or IRT should match the socially significant concern.
Exam Tie-In
Dimension questions often turn on the decision word. If the question asks how quickly behavior begins, choose latency. If it asks how long behavior persists, choose duration. If sessions vary in length, convert count to rate before comparing performance across days.
A BCBA compares aggression across sessions lasting 15, 30, and 45 minutes. Which measure supports the fairest comparison?
A supervisor asks whether a prompting procedure reduces the time between an instruction and the learner starting the response. What should be graphed?
Two teaching procedures both produce mastery. Procedure A reaches criterion in 18 trials with few errors, while Procedure B reaches criterion in 55 trials with many prompts. What concept best supports choosing Procedure A?