DESIGNED FOR THE USE OF OBSERVERS, TEACHERS, AND RESEARCHERS IN DESCRIBING CLASSROOM BEHAVIOR, THIS MODEL WAS SET UP IN 3 DIMENSIONS--CONTENT-SKILLS, CONCEPT LEVEL (DATA, CONCEPT, GENERALIZATION), AND STYLE (FOCUSING ON DESCRIPTION, EXPANSION, EXPLANATION, EVALUATION-EXPLANATION, AND EVALUATION). SUBDIVIDING CLASSROOM DISCUSSIONS IS ACCOMPLISHED THROUGH TOPIC, TOPIC DIVISION, TOPIC FOCUS, THEME DEFINITION, SUMMARIES, AND TOPIC RETURNS. CLASSIFICATION OF TOPICS IS BY CONTENT-SKILLS AND LEVELS OF ABSTRACTION (DATA, CONCEPT, AND GENERALIZATION). DISCUSSION STYLE INCLUDES DESCRIPTION, EXPLANATION, EVALUATION-JUSTIFICATION, EVALUATION-MATCHING, AND EXPANSION. AUXILIARY CATEGORIES COVERED ARE MANAGEMENT, STRUCTURING, AND ACTIVITY. DISTINCTIONS BETWEEN STYLE CATEGORIES ARE MADE, AND A CODING SYSTEM FOR CLASSIFICATION OF TOPICS IS INCLUDED. (AF)