A ten-year research study designed a mechanized information system in the information processing field. Special attention was paid to implementation criteria entering into on-line retrieval through man-machine dialog from a remote typewriter or video terminal and four major areas were investigated: search strategies, machine stored indexer aids, disc file organization, and graphic displays. The final system developed, SOLER, is a powerful library-oriented information system permitting browsing through the data base, narrowing of the search to selected files, and further restricting to chosen segments of each file. SOLER is useful to experts, indexers, and searchers, using the Real English search language--a complete English grammar--to permit users to engage in a full dialog with the computer. Other major findings include the following: 1) there is a significant difference between information, which is broad and qualitative, and data, which is formal, specific, and quantitative; 2) there are significant differences between information handling in library versus problem-solving environments; and 3) computerized library systems can extend the scope of catalog information and provide helpful indexing tools to users. (Author/LB)