Calibration of observational measurement of rate of responding.

The quality of measurement systems used in almost all natural sciences other than behavior analysis is usually evaluated through calibration study rather than relying on interobserver agreement. We demonstrated some of the basic features of calibration using observer-measured rates of free-operant responding from 10 scripted 10-min calibration samples on video. Five novice and 5 experienced observers recorded (on laptop computers) response samples with a priori determined response rates ranging from 0 to 8 responses per minute.