This project was an experimental effort to study, analyze, and understand interlibrary networks. The immediate purpose of the project was to develop methodologies for evaluating or analyzing networks; the ultimate purpose was to provide planning assistance to network funders, designers or operators. The project was conducted in four simultaneous phases. The Conceptual Model (Phase I) considered components of network design and performance and identified thirteen significant operational parameters. The Behavioral Model (Phase II) simulated network operations through "game playing" and further confirmed the validity of the Conceptual Model. In Phase III an effort was made to quantitatively analyze interlibrary networks in a Metropolitan Area. Significant operational variables were identified and measured. A Node-Network Dynamics Grid was developed to assist in evaluation and analysis of the Pilot Model Data. An Analytical Operations Research Model was developed in Phase IV to provide network planners with a tool for netowk performance prediction as a function of design options. A generalized network model called Lib-NAT (Library Network Analysis Theory) was developed and is presented. The methodologies developed in this project have been used by several states for network planning or evaluation and seem to be valid when properly applied. (Author/NH)