This paper reports on two comprehensive multi-institutional collaborative efforts for school improvement. The two studies demonstrate that collaborative efforts involving multiple agencies and multiple agendas can be successful even when separated by considerable geographical distance. The school systems were concerned with implementing a locally developed curriculum; researchers, meanwhile, were investigating the implementation process and providing training. The conceptual framework used in both programs, the Concerns Based Adoption Model (CBAM), is summarized. Its diagnostic dimensions (Stages of Concern about the Innovation, Levels of Use of the Innovation, and Innovation Configuration) are discussed. The planning, implementation, and evaluation of the two case studies are summarized: the Jefferson County (JeffCo) (Colorado) Schools program to improve elementary science curriculum and instruction; and the Palm Beach (Florida) Schools development and implementation of the Unified Curriculum program. The JeffCo case provides a clear example of a concerns-based implementation effort and illustrates how the diagnostic dimensions of the CBAM can be used to plan, monitor, and intervene in improvement efforts. Addressing teacher concerns is emphasized. The Palm Beach study emphasizes principal inservice training for the role of implementaion facilitation. The collaboration of research teams from schools mentioned above and from the Research and Development Center for Teacher Education at the University of Texas at Austin led to the formulation of seven key principles for school improvement; six important unresolved issues are also presented. (BS)