Microcomputer speeds and the new microcomputer storage devices permit the use of large data bases on microcomputers. In the past, speed and storage capabilities have been the primary hardware limitations preventing the use of large data bases on microcomputers. Although limitations still exist, in the near future microcomputers will perform most of the data base functions currently provided by mainframes. Efficient, flexible, and multiuser data base software has been developed to incorporate new artificial intelligence technologies that permit microcomputers to manage large data bases without the need for highly trained computer technicians. Many of the obstacles blocking the sharing of data bases among mainframes and microcomputers have been eliminated through the advent of new storage devices, modems, and networks. Because much of the data analysis software for microcomputers is interactive with graphical displays, more indepth and exploratory analysis is likely to occur with microcomputers than with traditional mainframes. The concepts discussed in this chapter are demonstrated using the example of Uniform Crime Reports data.