The nation's most important educational goal must be to produce learners adequately prepared for life and work in the 21st century. Computer- and network-based technology will play a key role in reaching that goal. In 1983, there was about one computer for every 125 students in the nation's public schools. By 1995, there was one computer for every nine students. In 1994, U.S. schools spent about $3 billion on computer- and network-based technology. Despite all this activity, however, examples of schoolwide use of technology are comparatively rare and isolated. This report identifies principles for guiding public officials, educators, and others concerned with increasing the use of technology to improve the performance of schools and school systems. Prepared as a result of RAND's Critical Technologies Institute (CTI) participation in federal efforts to plan a research agenda and develop a national educational technology plan, it is based upon a series of workshops, interviews, and literature reviews. This report takes stock of the current status of the use of technology by U.S. public elementary and secondary schools and suggests some of the challenges that face educators, policymakers, and producers of educational technology and software as they seek to expand and deepen the use of technology in schools.