This paper describes a study that addressed problems related to the disparity in achievement between disadvantaged and nondisadvantaged students. The first part of the study consisted of an analysis of three early intervention programs: the Responsive Early Childhood Education Program, the Reading Recovery program, and the Success for All program. The analysis identified program elements designed to improve student learning. From the analysis, objectives were developed to guide the second part of the study. These objectives were to: (1) identify successful models of intervention in the early grades; (2) examine how the implementation of early intervention strategies is related to the design of long-range disparity remediation plans; (3) develop, test, and evaluate a training module for principals who are implementing school-based disparity remediation plans. In the second part of the study, a case scenario that involved a desegregated urban school with a large number of low achievers was developed and incorporated into a training module, and the use of this module by eight elementary school principals was evaluated. The evaluation revealed that problem-based learning provided opportunities for new learning, produced a "think tank" experience for the participants, and improved the principals' awareness and understanding of related research. (DR)