The claims made for educational technology have not always been realized. Many programmes in education based on media and technology have produced useful documentation and supportive research; others have failed. The current, comprehensive definition of educational technology is a helpful key to understanding how a problem-solving orientation is necessary to approach teaching/learning designs. The process of educational technology begins with an analysis of the problem, rather than with the medium as a solution. Examples of appropriate applications come from open universities and primary schools where distance, time, insufficient personnel, and inadequate facilities have led to a search for alternative means for teaching and learning. Less successful programmes tended to have confused goals and an emphasis on one medium. They also lacked: support services, staff training, quality software and a system focus. The threads which run through the more successful programmes are described. The lessons learned from fifty years of media and technology development in education and training are discussed with an eye toward the future. It is clear that educational technology as a problem-solving process will lead the field into the twenty-first century.