The subject of this paper is the design of an economic data base system for public use, taking as a case study the Kentucky Economic Information System. This system offers its users facilities ranging from simple data retrieval and display to the capability to construct, maintain, and use econometric models online. It was designed originally to be user friendly to the trained econometrician, offering a semi-natural, verbal-mathematical free-format command language as the basic communication mechanism. However, with the development of the KEIS into a data base system that is widely used by government officials, academics, and others throughout Kentucky, the need has developed to provide a facility that is user friendly to any possible user. This paper considers the issue of user friendliness as a variable, depending upon the category of user. But it also considers tbe role played by the computer network and its operating conventions as a determinant of the user friendly features that are required. For example, in order to make the KEIS useable by reference librarians in universities, it was necessary to design a special interface; this necessity relates to the operating policies of the Kentucky Educational Computing Network, one of the computer networks the KEIS is resident upon. In addition, this paper considers the issue of user friendliness as it arises due to the specific characteristics of data and the operations performed: an economic data base system is inherently more difficult to operate than, say, a bibliographic data base system. Various other aspects of the KEIS have been considered in articles and papers appearing in such journals as the Journal of the American Society for Information Science and the Review of Public Data Use and in the proceedings of such conferences as the 1981 National Online Conference (March 1981) and the 8th European Urban Data Management Symposium, Oslo, Norway (June, 1981). A paper on the econometric modeling language (MODLER) that is available as part of the KEIS will be given at the 1981 Economic Control and Dynamics Conference, Copenhagen, Denmark (June 1981). This paper complements these other articles and papers.