This paper discusses an effective model of systematic staff development focusing on prevention and intervention strategies used with at-risk students. The following are key elements: (1) matching of the purposes of training to the goals of the school districts; (2) multiple and integrated activities; (3) participants' thorough orientation to the purpose and content of the development activities; (4) opportunities for collaboration among school staff such as information sharing, observing, mentoring, peer coaching, and planning; (5) ongoing opportunities for practice and information sharing; and (6) follow-up support and assistance between training sessions. The characteristics of effective training sessions and the contextual factors are briefly described. To address the unmet educational needs of the at-risk student population, the in-service training plan should be: (1) comprehensive, including detailed teachers' manuals, curriculum materials, lesson guides, and supportive material; (2) intensive, using one-to-one tutoring or individually-adapted computer-assisted instruction; (3) flexible, using student progress assessments to modify groupings or instructional content; and (4) preventive, emphasizing that students learn to read the first time they are taught. Schools can develop feasible programs to ensure that every child learns, but it will take effective in-service training that is individually tailored to meet those program goals. This paper contains 10 references. (ALL)