A brief review of the literature concerning the relationship between self-concept and academic achievement precedes a discussion of the perceptual and operational models of self-concept as they relate to classroom teaching. It is suggested that the differentiated "operational" model of definition and instrumentation of self-concept best meets the needs of students. This model is based on the operational definition that "self-concept is an individual's repertoire of self-descriptive behaviors," and is directed toward better understanding of school-related and non-school-related tasks that confront students. It is also suggested that the understanding that results from this model makes it easier for teachers to design appropriate and effective Individualized Education Programs and reduce the use of labels and categories for students. (CB)