This paper discusses a number of contingency arrangements used in studies at the University of Kansas to enhance individualized characteristics of personalized instruction. It begins with an examination of Keller's Personalized System of Instruction (PSI) and its five defining features: (1) reliance on the written word, (2) unit mastery, (3) the go-at-your-own-pace feature, (4) motivational lectures, and (5) the use of proctors. It argues that the core of personalized instruction is the unit mastery requirement which stipulates that students cannot progress from one unit to the next until the previous one has been mastered, and that all other PSI components only serve to enhance the unit mastery concept. Finally, the paper outlines several studies conducted at the University of Kansas and elsewhere which were designed to use contingencies to make personalized instruction more dynamic and flexible, and to make group-based classes more responsive to individual student needs. Ten references are listed. (MER)