This paper is concerned with the research and development work that is being undertaken in applying interaction analysis to the training of university lectures. Interaction analysis or the systematic observation of lecturing is a technique that has been used in conjunction with microteaching to facilitate the trainer's job in shaping the teaching behavior of the lecturer. A category system was devised to describe the content of lectures, focusing on teaching points, examples, instructional asides, and non-instructional asides. The paper reports on how university lecturers are trained in the system and how they learn to record data collected from their lecturers. These low inference data are then used in microteaching sessions where the lecturers record on videotape their performance for peer and trainer criticism. The systematic observation data are used to make more objective the trainer's criticism of the microlectures and to provide evaluative data for improving teaching performance. (Author)