This study investigated the methods and effects of introducing a teacher development program aimed at improving student learning across the curriculum at two secondary schools in New Zealand. A particular target was the lowest achieving 30 percent of learners who were identified as "less proficient learners." The teachers were volunteers drawn from the whole staff of each school. The study focused on how teachers took up the opportunity, the effects of the program on their beliefs and practices, effects on student beliefs and practices, changes in student academic and social behavior, and costs of implementing the program on a wider basis. Data were gathered through teacher and principal questionnaires and interviews before and after the project, teacher reports and diary notes, comments from working meetings and interactions with students and teachers, and student test results. Among the findings from the data analysis were: teachers did reorient their delivery of curriculum material and the environment in their classrooms in accordance with developing literature on effective classrooms and in a personally reflective way; a collaborative style of work developed among the teachers that reflected the cooperative group learning programs the teachers were establishing in their classrooms; and students demonstrated increased abilities in use of learning strategies and in subject materials. Appendixes contain data on tracing advance organizers; questionnaire definitions for teachers, students, and principals; and advisory committee meeting definitions. (JB)