As part of their study of interorganizational collaboration, researchers present three detailed case studies of how regional education agencies (REAs) supply knowledge utilization services to the school districts they serve. The three REAs are the Wayne County (Michigan) Intermediate School District (with 36 districts), the Educational Improvement Center-South in New Jersey (144 districts), and the Northern Colorado Educational Board of Cooperative Services (six districts). Each case study describes the REA and its knowledge utilization activities, the interorganizational arrangements for knowledge utilization services, the outcomes of the services, and the reasons why the services are used. The knowledge utilization services examined fall into four areas, including information retrieval, linking agent assistance, staff development, and general organizational issues. Analysis of the services' levels of use indicates that the Michigan and New Jersey REAs are more successful that the Colorado REA. The reasons for this difference have more to do with service credibility, interpersonal ties, responsiveness to user needs, mutual exchanges, and external financial resources and less to do with compliance with state laws (except in New Jersey), formal interorganizational agreements, or conflict reduction among the participating organizations. (RW)