The practice of student grouping from the perspective of critical school district involvement in the proposed program is examined in this report, with a focus on the relationship between grouping program outcomes and the degree of district support. Four school districts in Texas participated in two substudies: the first examined the performance of 176 high-ability third- through fifth-graders in a magnet school, a continuous progress district, and traditional schools, and the second examined the mathematics performance of 223 lower general ability fifth-graders in a continuous progress district, nongraded school, Chapter 1 school, and cluster-grouped program. Pre- and post-tests were administered to the children in each study. Continuous program students consistently ranked at the top in areas of mathematics, computational skills, and conceptual skills mastery, suggesting that district commitment is crucial for student achievement despite the grouping practice utilized. Seven tables are included. (11 references) (LMI)