Controlled school choice attempts to provide choice while maintaining ethnic and racial integration. The following elements are found in most controlled-choice plans: (1) any program that is successful in one zone must be replicated in all the other zones; (2) parent information centers are available to help parents make educated choices; (3) low-performing and unpopular schools are assisted in their efforts to improve; and (4) clear assignment criteria are utilized to avoid subjective and unfair assignments. Most controlled-choice districts assign about 75 percent of students to their first choice, and 10 percent to their second choice. Evidence from Cambridge, Massachusetts, indicates that controlled choice has been improving educational quality. (8 references) (MLF)