By studying the process by which disadvantaged and low-achieving high school students are assigned to classes and special programs, how and why disadvantaged students are placed in inappropriate programs can be understood. Reasons exist to question the assumption that students are assigned to programs rationally on the basis of information about abilities, performance, and interests. Ideal characteristics of scheduling processes were identified based on the literature, and compared with practices in four urban high schools. Multiple methods of data collection, including interviews, reviews of school records, and observations of events related to scheduling, were used. Findings from the four schools indicate the degree to which each conforms or deviates from the following ideals of assignment: (1) appropriate for ability level; (2) class size appropriate for the type of instruction; (3) courses that fill graduation and college admission or employment requirements; (4) times that students are likely to attend; (5) effective teachers; (6) course assignments made before the beginning of the term; and (7) programs match student interests and needs. Recommendations for improvement of the assignment process are made. Thirty-six figures illustrate the discussion. Three appendixes contain interview questions, the interview format, and a course change form. (SLD)