This evaluation of the first-year elementary school implementation of Boston's pilot "controlled choice" student assignment plan found that very little had been accomplished in planning for school improvement and that future desegregation compliance hinges on key decisions about secondary and bilingual education, and the empowerment of administrators, school staff, and advisory councils. The controlled choice assignment plan gives parents the opportunity to indicate preferences for the schools their children will attend and also stimulates school improvement. The plan includes school improvement councils that advise the zone superintendent on the use of state and Federal funds to strengthen schools unable to attract applicants. The new student assignment process did not resegregate schools, as some had feared, despite problems with ambiguous language in the plan, too many white students assigned to kindergarten seats, and lack of an appeals process. Problems with parent information and recruitment were related to delays in decision-making by the superintendent and the school board and to insufficient clarity about which decisions should be made by zone superintendents. The potential for school improvement that is an implicit and essential part of a choice plan has been forestalled by the failure to link the results of parent choice with school-level improvement plans. The plan cannot be extended to high schools until issues concerning the location and size of bilingual programs and curriculum reforms have been decided. Statistical data are included on ten tables. (FMW)