This self-instructive workbook focuses on the identification of a set of classification abilities related to learning. It utilizes written materials, videotapes, and students, and is supplemented by a program and support system which includes instruction, teaching experiences for practice, discussion, and individual conferences. The three major goals of this workbook are to enable the teacher to (1) use a clinical method to administer, at any grade level, diagnostic tasks related to classification abilities, (2) identify the developmental level each student in the class has attained in terms of classification abilities; and (3) select, from resources available, subject matter appropriate to identified levels of development. Classification ability tasks are included which deal with different types of sorting and reclassification. The workbook contains outlines for eight self-workshops, some of which involve (1) assessing the ability to administer classification tasks, (2) administering classification tasks to students, (3) identifying levels of classification abilities, and (4) matching experiences to levels of development. The workbook also includes exercises in identifying classification abilities related to mathematics, in introducing the concept of "horizontal instruction," and in pictorial and symbolic sorting. There is a section dealing with a review of research on classification abilities and a bibliography. (BD)