Agencies need to collaborate with each other to perform missions, improve mission performance, and find efficiencies. The ability of individual government agencies to collaborate with each other for mission and business success and efficiency is complicated by the different techniques used to describe their Enterprise Architectures (EAs). Reference models to federate EAs across multiple agencies are investigated as a means to enable this collaboration. While heuristic and qualitative approaches to federating EAs have led to the increased use of reference models, their actual effectiveness and value have not been quantified and validated. Federal departments and agencies are under increasing pressure to meet mission and business goals with improved efficiency. EAs are used to align agencies strategic goals and business objectives to resources. As agencies collaborate with each other to achieve better strategic performance and resource savings, the ability to share information about their EAs is critical to their success. The expected effectiveness of reference models in federating EAs was quantified and validated employing the classical method of expert judgment. A structured discussion instrument to evaluate reference models was developed and piloted using well-established guidelines for expert judgment. The resulting instrument was used in structured discussions with architects and engineers who are members of an architecture working group across multiple federal government agencies. Reference models were determined to be effective for federating EAs where participating agencies align their component architectures to the common taxonomy provided by the reference models. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]