This paper describes a training program which was designed to train teachers how to use computer applications such as database management systems and spreadsheets in their classrooms; how to modify applications according to their teaching practices; and how to learn from their experiences in using computer applications in the classroom. A group of 14 secondary science teachers participated in the program, which lasted for 25 days and included 10 days of training in computer science literacy and 13 days working in groups to develop software for teaching science and integrating the computer as a tool in their classroom practices. The training was also intended to help teachers recognize their own underlying theoretical constructs and to choose appropriate software that would mirror those constructs. In their efforts to accomplish these goals, teachers paid particular attention to their own learning processes, and to their role as manager of an educational environment. Also discussed is the "accompanying" role of the training of trainers during the development process, including the management of teachers' affective and cognitive resistance to changes in their practices required by the use of new media. (DB)