An analysis system was developed to facilitate the comprehensive analysis of over 800 hand-written mathematics, communications, and social studies lesson transcripts. The coding scheme facilitates the reduction of qualitative data into categorical data. The heart of the analysis system is the Dominant Instructional Event (DIE) which facilitates the further subdivision of each lesson into subcomponents labeled content, materials, groupings, interaction patterns, student activities, and cognitive taxonomic level. Trends are reported to illustrate the utility of the analysis system, however the paper focuses primarily on the methodology and the potential importance and estimated validity of the analysis system. (Author)