Student achievement in grades kindergarten through four in the partial immersion program of the Ottawa Roman Catholic Separate School Board was investigated. Achievement in English and French language arts, mathematics, social studies, and science was assessed using instruments referenced to learning objectives. Student and teacher background questionnaires were also developed and used in the study. The results are reported and compared to those of students in unilingual programs. The overall results show that the partial immersion students are performing satisfactorily and comparably to students in other programs. A more detailed analysis of the results reveals ways in which the instructional emphases limit students' learning and performance. Program objectives that emphasize applications to real-life situations are among the least taught in the program. Therefore, performance is weakest in these areas and strongest in the most passive skill areas such as listening. Recommendations are made regarding policies, resource personnel, and followup testing. Evaluation instruments, criteria, questionnaires, and results are appended in a separate volume. (RW)