The usefulness of Biglan's model of academic disciplines for examining how Yale University departments differ in their evaluations of undergraduate performance is studied. Biglan's 3-way model classifies departments according to (1) the degree to which they have a paradigm (hard vs. soft), (2) their concern with life systems as objects of study (life vs. nonlife), and (3) their emphasis on application (pure vs. applied). The present study, undertaken at Yale University, finds that the hard-soft classification most clearly differentiates how faculty evaluate student performance, showing significant differences for descriptions of real, successful students, for ideal use of 21 varied dimensions of student performance to evaluate success, and for ideal use of these dimensions to evaluate nonsuccess. Life and nonlife departments also differ significantly in their use of the 21 performance dimensions to describe successful undergraduates. The aspects of student performance that are stressed by the different faculty groupings of hard and soft, and of life and nonlife disciplines are also explored. (Author/MSE)