Tables showing the types of Educational Resources Information Center (ERIC) products and their dispersion provide background information for the executive summaries of usage study design reports focusing on three levels: (1) system operations; (2) subscribers to the services provided; and (3) the ultimate "end-users" of the service. The summaries emphasize the important points of each type of study. The first level report addresses ERIC as an information network and describes a framework for comprehending, examining, and managing the ERIC system. It also describes useful data categories and appropriate levels of data collection; suggests a method of developing a model data system; and examines these suggestions with respect to current possibilities. The second level report recommends non-experimental approaches to ERIC use assessments and examines methodological and research design considerations for usage studies. The third level report focuses on ERIC impact studies and analyzes them in terms of methodological recommendations and specific impact studies are included. A bibliography of ERIC usage/impact studies is also included. (CWM)