A study examined the specific differences in the salary reward systems of eight clusters of academic disciplines included in Biglan's three-dimensional model of the academic profession. The sample consisted of 1,320 faculty at a large research university who responded to the Faculty Activity Analysis questionnaire requesting information on the amount of time they devoted each week to eleven categories of professional responsibility. These measures were used to predict faculty salaries in the eight discipline clusters by stepwise, multiple regression procedures. The results demonstrated wide variation in the reward systems of these discipline clusters. (Author/MSE)