"What's Your Thinking behind That?" Exploring Why Biology Instructors Use Classroom Discourse.

Instructor discourse, defined as verbal interactions with students in the classroom, can play an important role in student learning. Instructors who use dialogic discourse invite students to develop their own ideas, and both students and the instructor share ideas in back-and-forth exchanges. This type of discourse is well-suited to facilitate deep learning for students but is rare in undergraduate biology classrooms. Understanding the reasoning that underlies the use of dialogic discourse can inform teaching professional development for instructors who are learning to use discourse to support student learning. Through classroom video recordings to identify dialogic discourse and stimulated recall interviews to elicit instructor reasoning, we investigated why undergraduate biology instructors used dialogic discourse in active-learning lessons. Using inductive and deductive qualitative analysis of interview transcripts, we identified and characterized seven reasons that instructors used dialogic discourse, including three aligned with a theoretical framework of student cognitive engagement and four that emerged from our data set. In addition to aiming to prompt generative cognitive engagement in 34% of instances of dialogic discourse, instructors used dialogic discourse to prompt activity, supply information, provide feedback, decipher student thinking, leverage student thinking, and cue students to make connections. Reasoning varied across different types of dialogic discourse. These findings provide valuable insights that can inform research, teaching professional development, and individual instructors' reflections.