Three schools in the Kansas City, Missouri, School District have operated for 5 years as Investigative Learning Magnet Schools (ILMS). The ILMS emphasize such student outcomes as inquiry, problem solving, critical thinking, and observation skills, and have a curricular focus on science, math, and computer skills. This report examines the ILMS' student achievement and enrollment during 5 years of operation under a court-ordered desegregation plan. Covering the period between 1986-87 and 1990-91, the report presents achievement gains or losses as measured by the Iowa Tests of Basic Skills (ITBS), Missouri Mastery and Achievement Test (MMAT), and Degrees of Reading Power Test (DRP). In addition, data on enrollments, racial composition, and extended-day participation are presented. Highlighted findings include the following: (1) ITBS achievement outcomes for students enrolled in the ILMS generally remained above national and district norms; (2) between 1986 and 1991, minority students showed gains of at least 5 percentile points in achievement scores in reading in kindergarten through third grade, while nonminority students showed gains in 2nd grade but losses in fourth and fifth grade; (3) nonminority student cohorts had consistently higher scores across years than minority student cohorts; (4) in comparison to students in traditional schools, ILMS students performed significantly better in reading, language, math, and science; and (5) the ILMS are close to court-ordered racial composition goals, with nonminority enrollment remaining relatively stable in the past 3 years. (AC)