The research reported in this document represents efforts to search for the structure and dynamics of the instructional process itself. Without reliable knowledge of these basic facts, improvement of teacher education and the guidance of teachers would remain based on unsystematic experiences and speculation. In order to penetrate the structure and dynamics of instructional processes, an instrument for the description of what is going on during the interaction, or a taxonomy for classification of observational data, is necessary. Different taxonomical procedures already developed were utilized for the description of instruction. This document describes a) the development of the instrument for the description of instructional processes, b) the taxonomy of the Helsinki Didactic Process Analysis project, and c) the aims and design of the project's second phase. (DDO)