Abstract
The various relationships between differential reinforcement procedures and behavioral variability are discussed with reference to experimental studies. The research of behavioral variability was classified into two categories: the collateral change of response variability in operant conditioning; and increasing behavioral variability by differential reinforcement procedures. The variability of response sequences is increased by three types of differential reinforcement procedures: the lag schedule; the frequency dependent reinforcement schedule; and differential reinforcement of switching. The discussion identifies two problems regarding the functional behavioral unit established under differential reinforcement procedures: the building blocks of reinforced responses, and reinforcing effects on the building blocks. Research of these problems could explore the function of differential reinforcement procedures and the disposition of behavioral variability more precisely.
