Precision Teaching has its roots in free-operant conditioning laboratories. Free operant means that "students are free to respond at their own pace without having restraints placed on them by the limits of the materials or the instructional procedures of the teachers" (Lindsley, 1990b, p. 10). During the 1950s, Ogden Lindsley was successfully applying these methods to the behaviors of psychotic children and adults at his Harvard Behavior Research Laboratory. His research was showing "frequency to be 10 to 100 times more sensitive than percentage correct in recording the effects of drugs and different reinforcers" (Lindsley, 1990b, p. 10). He was painfully aware that when researchers applied their methods, even behavioral methods, to academic behaviors of school children, they typically recorded only percentage correct, "the time-honored educational measure." He attempted to change this practice by urging visiting educators to his laboratory to standardize the frequency of response in their classrooms. He recalls:
In 1965, Lindsley shifted his focus to special education teaching training. His initial aim was to introduce free operant technology into public school classrooms.
Lindsley goes on to say that he and his colleagues "were successful beyond our dreams." The aim was met within three years. One key development during that time was a standard chart for teacher and student recording. Since then, Lindsley and colleagues have collected data from thousands of these charts, resulting in a number of inductive, counter-intuitive discoveries, some of which will be described later in this module (for a complete summary, see Lindsley, 1990a; 1995; also Binder, 1996).