In contrast to the usual approach in computer-based reference services, which is to go into a specific data base to retrieve citations to material on a specific, narrowly-defined topic, this report demonstrates how such services could be useful in a broad approach to a complex subject, using an investigation of trends in the world aluminum industry as a case in point. The user's request was broken down into three questions; eight of the 75 data bases available were finally used. A controlled, phased exploration of these data bases was conducted. At the conclusion of each phase, the recovered citations were cataloged, analyzed, and compared. Tentative conclusions were drawn, and the exploration redirected if indicated. The approach was successful in that it produced a wealth and variety of information, was cost-effective if one considers what a librarian would have to do to produce the same results using manual search methods, and seems cost-beneficial from the point of view of efficiency, precision, and effectiveness. Appendices present the search histories of the study by question and data base, the respective times online for the searches, a description of the data bases, descriptive statistics of the results, a cost-comparison of man and machine, tables of bauxite producers and aluminum companies, and a consideration of the precision obtained. (JD)