The purpose of this study is to investigate the quality of class talk during episodes corresponding to different levels of generalization. A total of 10 sessions in two classrooms in grade 7 were videotaped. A mixed approach was adopted to analyze the videotaped sessions. The findings show that triadic dialog was the dominant mode of interaction during class talk. The teacher's general teaching approach was inductive with a tendency to dialogic teaching, although there were some indicators to univocal class talk. This tendency to use dialogic teaching was due to shifts between generalization level episodes (at a macro level) and among knowledge types within episodes (at a micro level), which influenced the quality of class talk. Besides, the teacher played the role of secondary knower, thus allowing dialogic discourse during class talk. Furthermore, in almost all episodes, it was the teacher who initiated the episodes, and he frequently started the majority of exchanges. Triadic dialog in class talk and the multiplicity of teacher's roles, as initiator and secondary knower, helped to elicit various levels of generalization.