The Teacher Observation Scales include four instruments: Observer Rating Scale (ORS), Reading Strategies Check List, Arithmetic Strategies Check List, and Classroom Description. These instruments utilize trained observers to describe the teaching behavior, instructional strategies and physical characteristics in each classroom. On the ORS, teacher behavior is rated on nine dimensions: warmth, enthusiasm, clarity, variety, individualization, feedback, cognitive demand, freedom, and on-task activity. The checklists provide broad categories which represent the major instructional strategy or teaching mode employed by the teacher. The Classroom Description describes the classroom environment in terms of materials, lighting, physical conditions, and whether the class structure and method of instruction appear to be traditional, open-concept, or experimental. Instructions for all four instruments are included. (Author/SM)