Through a Pennsylvania statewide curriculum integration project involving 11 school districts, this research examines the curriculum reform process and determines which factors, or combination of factors, are absolutely essential for successful curriculum reform. Comparing programs and their respective levels of success makes it clear that only a subset of factors are essential elements. The research used a qualitative, multisite, modified analytic induction design. Twenty-three factors thought to be essential for curriculum reform were identified, and a systematic curriculum integration framework was developed for use in the 11 districts. The factors were categorized into: (1) resources; (2) teacher teaming; (3) administrative involvement; (4) curriculum issues; and (5) communication. Exploration of these areas shows that resources are an essential component, and that all involved need to find creative ways to reallocate both financial and human resources. Teacher teaming is another necessary and evolving process, because shared ownership is crucial to success. Administrative involvement is basic to the success of the team. Curriculum revisions drive the reform process, and they must express clear goals that are owned by everyone. Communication to all constituencies is another essential. (Contains 1 figure and 10 references.) (SLD)