The System for the Classroom Observation of Teaching Strategies (SCOTS) is described. The schedule requires a higher level of inference by the observer than many researchers may find acceptable. The paper argues that inference can be controlled within acceptable limits and that issues of objectivity and subjectivity are very complex. The SCOTS schedule attempts to reduce observer bias by concentrating on 43 separate variables believed to be parts of a teacher's teaching style or strategy. The observer places the teacher under observation on a defined continuum for each variable. Each continuum consists of five points, thus making each variable a multiple choice item for the observer. The items cover such topics as teaching skills, feedback and individual aid, pupil interest and motivation, development of responsibility, grouping practices, efficiency of management, authoritarianism and coercion, class control, and relationships with students. Appended are the complete SCOTS schedule by John L. Powell and Mabel N.G. Scrimgeour (1977 Revision) as well as items of a summative version that differ from the classroom version. (DWH)