ABSTRACT
In the context of the COVID-19 pandemic, the paper focuses on discussing this important teaching segment online in blended learning. Taking the junior as the research objects, the behavioral characteristics and interaction depth of different types of students are studied through Cluster Analysis and Lag Sequence Analysis. The purposes are to dig out the problems existing in the online discussion process and to propose teachers' intervention suggestions so as to improve the effect of the discussion. The research found that discussion behavior is mainly construction, and there is no discussion mechanism with communication and interaction as knowledge development. The behavior transformation is mainly based on the priming-single type and priming-arguing type, and there are fewer students who achieve the ideal state of the argumentative type. Most students integrate into the discussion atmosphere slowly, so teachers should take corresponding measures to help students enter the discussion quickly at the beginning of the discussion. © 2022 ACM.