Final answer:
Latency is the time delay between the occurrence of a stimulus and the response to that stimulus. In this case, a Behavior Technician measuring Andrew's response time to someone calling him would be measuring latency.
Step-by-step explanation:
If a Behavior Technician measured the length of time that it took Andrew to respond to someone calling him, she would be measuring the latency. Latency is the time delay between the occurrence of a stimulus and the response to that stimulus. In this case, the stimulus is someone calling Andrew, and the response is Andrew's reaction to the call. By measuring the latency, the Behavior Technician can gather data on Andrew's response time.