Incorporating small-group discussions in classrooms has shown promising benefits in improving 4th grade students' thinking and social skills; however, the practice remains challenging. Although teachers are motivated to try to incorporate small-group discussions, studies examining the shift from teacher-dominated classroom practice towards a more dialogic pedagogy are scarce. This study sought to explore the role of teacher group reflection on teacher's learning to implement discussion-based teaching referred to as Collaborative Reasoning Discussion. Drawing from theories on reflective teaching and professional learning communities, seven transcripts of teacher reflections and 12 transcripts of facilitations were examined using line-by-line microanalysis and a linguistic ethnography analysis approach. Findings indicate that teacher group reflection served as a key role. Reflections not only provided opportunities to be aware of essential aspects and conflicts during implementation, but also offered strategies to deal with the conflicts. The results of the study provide deeper insights about the process of adopting a dialog-based pedagogy and the key role of group reflection in the process. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]