In spite of the presence of volumes of research literature about cooperative and independent learning, there are only a few publications regarding the role and effectiveness of the teacher in pair and group work respective to the initiation and accompaniment of student-active educational dialogues. On the other hand, it is known that not all the dialogues and interactions that take place in cooperative arrangements show the quality features that pedagogues and teachers like to proceed from. On the basis of current explanatory hypotheses on the use of cooperative teaching and learning models, the following article discusses the quality of dialogues for a multi-critical procedure of partner- and group work. Subsequently, it addresses the function of teachers regarding the obtainment of this quality. Finally, conclusions are drawn as to the orientation of research into the teacher and learner's roll that accompanies dialogical teaching.