Productive classroom discussion has been shown to support student learning across academic domains. Facilitating successful discussion hinges on the teacher's ability to make adept in-the-moment observations of various aspects of student talk and classroom dynamics. In two studies, we explore a pedagogical intervention using contrasting cases to support novice teachers in learning to notice key features of classroom discussion. Study 1 involves preservice teachers in a bilingual teaching methods course in a university-based credential program. Study 2 involves undergraduates in an education psychology course, many of whom are prospective teachers. Study participants engaged in analyzing transcript-based contrasting cases of discussion vignettes as they collaboratively developed guiding principles for effective class discussion. Data include pre- and post-instruction video noticing task reflections, principles identified, and transcribed partner discussions during the activity. Post-instruction, learners displayed increased student-centered noticing when watching videos of classroom discussions. Additionally, there was increased awareness of the absence of productive features or missed opportunities within the discourse. In this proof-of-concept set of studies, we explore the potential of contrasting cases-based activities to help prepare teachers for the complex task of orchestrating discussion by supporting them in learning to notice.