More than 100 classroom communication observation instruments are surveyed and assessed from a communication-based perspective in this paper. In an overview, a schema designating three main types of approaches is established; they include behavioral descriptive, message functional, and cognitive/affective inferential observational categories. Next, the paper presents an application of a communication perspective to a critical assessment of the techniques; this application centers around the areas of verbal/nonverbal behavior descriptive potential, sensitivity to noting participant interactions, teacher/student behavior perspectives, and classroom roles and ecology biases. Following a close examination of three significant techniques, a commentary concerning their values and limitations as communication observation systems is offered. The paper concludes with recommendations concerning criteria for selection of an instrument. (Author/FL)