Relative and Absolute Strength of Response as a Function of Frequency of Reinforcement1,2

pigeons behave on a concurrent schedule under which they peck at either of two response-keys. The signifi-cant finding of this investigation was that the relative frequency of responding to each of the keys may be controlled within narrow limits by adjustments in an in-dependent variable. In brief, the requirement for rein-forcement in this procedure is the emission of a mini-mum number of pecks to each of the keys. The pigeon receives food when it completes the requirement on both keys. The frequency of responding to each key was a close approximation to the minimum re-quirement. The present experiment explores the relative fre-quency of responding further. In the earlier study it was shown that the output of behavior to each of two keys may be controlled by specific requirements of out-puts. Now we are investigating output as a function of frequency of reinforcement. The earlier experiment may be considered a study of differential reinforcement; the present one, a study of strength of response. Both experiments are attempts to elucidate the properties of rdlative frequency of responding as a dependent vari-able.