Abstract: A multi-user system for creating and maintaining a knowledge base is implemented on a variety of computer systems, including single-user personal computers, networked personal computers, and data communications networks, including the Internet. The system has a graphic user interface which can be easily learned by non-programmers. The knowledge base is displayed as a hierarchical multiplicity of nodes, in which each node is related to one or more superior nodes. Title of text, rules, references, and attributes associated with each node are displayed, and may be modified. Simulation is used to verify the knowledge base once generated. Data may be extracted from the bases in the form of hard-copy books, databases for downloading into Web browsers, and databases for downloading into hand-held computers including a multiplicity of grids, and a multiplicity of branches in the form of a logic tree.