A First Year Biology Teaching Development Group (FYBT) was set up in 1993 to introduce computer-based materials into a first year biology course, which is taken by about 800 students. The main aim of FYBT is the development and introduction of 20-30% computer content into each laboratory class, including a variety of co-operative learning experiences that will target development of student self-directed learning and communication skills. This paper focuses on: the development, evaluation and introduction of computer-based materials and the resulting changes in the management of the course; the expected teaching outcomes; and students' perceptions of the teaching changes. FYBT has introduced computer-based student registration, computer-delivered and marked formative and summative quizzes and numerous teaching modules on a Macintosh computer network. The teaching modules have been assessed by staff and students, during their development and introduction into the classes, and their response to the computer-based materials is positive and encouraging. Evaluation of the effectiveness of the modules is being undertaken.