What term describes a special form of event recording that measures the number of responses or practice opportunities needed to reach a pre-established level of accuracy or proficiency?

• A. VARIABLE INTERVAL
• B. TRIAL TO CRITERION
• C. VARIABLE RATIO
• D. VERIFICATION

Answer: (B)

Trials to criterion counts how many practice opportunities a learner needs to reach a predefined level of accuracy or proficiency. Each trial is a discrete opportunity to respond, and the count stops once the learner meets the set criterion (for example, a target percent correct). This measurement focuses on learning rate and mastery, not on when or how often reinforcement occurs during ongoing responding, which is what reinforcement schedules describe. Verification is not the measure described here; it relates more to confirming data accuracy rather than tracking the number of trials to mastery. So, this term best fits the description.