This paper outlines the history of paraprofessionals and reviews the reasons for their use. However, its main focus is on the specific ways in which these people are currently being used in the schools. The authors discuss the two major kinds of paraprofessionals -- service-oriented and instructional -- and analyze the various methods that have been proposed for selecting, training, and certifying them. The legal aspects of paraprofessional programs are covered, and the sometimes delicate relationship between paraprofessionals and teachers is explored. A selected bibliography is included. (Author)