The impact of technology on teaching is explored. Technology alone cannot affect the ways in which teachers and students interact, but it can affect teacher roles in several ways. Teachers may feel that computers will replace them, or they may regard technology as just another tool. Some teachers believe that technology can transform curriculum, the teacher's role, and even school structure. In fact, technology can support traditional or learner-centered instructional philosophies, but teacher use of technology is generally influenced by their knowledge of the technology, access to instruction and support, and incentives that favor teacher use or disuse in the classroom. Teachers who do adopt a technology-based approach normally progress from being a presenter of knowledge to being a coordinator of learning resources, being freed to work individually with students. Technology can be a medium of instruction or it can be a tool in support of the goal of teaching for understanding. Teacher-centered teachers tend to use traditional instructional methods and to regard learning technologies as basic skill reinforcers, motivators, or special treats. Learner-centered teachers usually choose individualized or collaborative approaches to engage students. Learner-centered teachers may be high technology users, or they may be reluctant to use technology because of personal fears and inhibitors. For successful technology use, teachers must be flexible in the roles they play. (SLD)