Twelve learner characteristics and 26 demographic characteristics of entering preservice teachers were investigated to determine if the presumption of homogeneity was valid in relation to selected learner characteristics and to discover which, if any, demographic characteristics could serve as predictors of learner characteristics. The study also laid the groundwork for a series of trait-treatment studies. During the fall of 1974, 400 Indiana University students, randomly selected from a total of 700 registering for an education course, were asked to complete a questionnaire packet including four instruments: (1) a survey of background information; (2) a measure of interpersonal needs; (3) a measure of attitude toward open and traditional education; and (4) a measure of perception of the role of the teacher. The findings suggest that while entering preservice teachers exhibit variance in the learner characteristics of interpersonal need, attitude towards open and traditional education, and perception of teacher role, this variance is not related to the background characteristics surveyed. Background characteristics, therefore, are poor predictors of the learner characteristics of entering preservice teachers. While there are some apparent exceptions, the considerable variance found in the learner characteristics suggests that the presumption of homogeneity implied in current teacher education practices is largely unfounded. This variance suggests that uniform modes of teacher education need to be seriously reexamined and, specifically, that teacher education would profit from individualized practices. (MM)