This master's project analyzed the implementation of a program designed to address the academic needs of all students in a heterogeneous classroom. The targeted population consisted of secondary parochial school students from working and middle class backgrounds in or around a large midwestern metropolitan area. Problems of underachievement were documented through surveys, interviews, and teacher observations. Analysis of probable cause data revealed that teachers tend to teach to average students and do not sufficiently address the special needs of the upper and lower ability ranges, resulting in students not being actively engaged in the learning process and failing to take responsibility for their learning. Three major categories of intervention were selected to incorporate higher-order thinking skills into students' daily activities: the integrated use of cooperative grouping techniques, the implementation and monitoring of student goals, and the development of student awareness of the intelligent behaviors concept. Results showed that students of all classes improved at the low end of the ability range, and three of the four classes improved at the average and high ends of the ability range. This seemed to indicate that using project-based learning to implement cooperative grouping, goal setting, and intelligent behaviors was beneficial to most students. (Appendices include funding sources, administrative study, teacher survey, sample lessons and projects, and an intelligent behaviors self-assessment survey. Contains 21 references.) (Author/EV)