Three papers exploring facets of the teaching process are presented in this report. The papers are part of the Didactic Process Analysis (DPA) Helsinki research project. The DPA research team, composed of educators investigating instructional processes, has, since 1967, examined taxonomies and classifications of teaching processes. The first paper, "Investigations into the Instructional Process (DPA Helsinki)" describes the background, goals, and approach of the DPA team. Research was conducted on the development of a DPA classification of instructional events, joint lesson planning by teachers and students, and the use of the DPA taxonomy in characterizing the instructional process in selected classrooms in Finland. In the second paper, research on teacher decision making is reviewed. One study in particular is cited because it showed that teachers did not plan lessons on the basis of objectives. The thesis of the third paper is that conflicts in terminology present a barrier to effective teacher education. A comparison of taxonomies is offered, and the DPA paradigm of instructional processes is introduced. References follow each of the papers. (FG)