Define 'latency' in the context of behavior measurement.

• A. The total time of the response.
• B. The time from the onset of the response to the end of the behavior.
• C. The time between consecutive occurrences.
• D. The time from antecedent or instruction to onset of the response.

Answer: (D)

Latency is the time from the delivery of an antecedent or instruction to the moment the person begins the target response. This starts at the cue and ends at the response onset, capturing how quickly a learner initiates behavior after instruction. It’s distinct from duration, which measures how long the behavior lasts once it starts, and from interresponse time, which is the gap between consecutive occurrences of the behavior. So the defined option—time from the cue to the onset of the response—precisely reflects the initiation latency behavior analysts measure.