Teacher professional learning communities (PLCs) are a valuable tool that increase teacher collaboration to enhance student learning. These adult learning environments are dynamic in that they are places where adults are able to work within a community of practice (CoP) to address work-related challenges and lend support in semi-structured meetings. It is important, therefore, to create supports that increase effective collaboration between teachers as they engage each other around problems of practice to increase student learning. The intent of this intervention study was to examine the impact of reflective prompts rooted in behaviors associated with effective collaboration as defined by a Thomson et al. (2007) study on teacher behavior in PLCs. The hypothesis of the researcher was that reflective prompts could significantly impact participant behaviors toward more effective collaboration, as well as increase dialogue moves associated with collaborative argumentation rooted in a 2001 Kuhn and Felton study. Qualitative coding and frequency analyses were conducted to examine the impact of reflective prompts on teacher behaviors both seen and perceived. Analyses revealed that reflective prompts have no significant impact on how teachers used dialogue moves; however, there is evidence that participants did change behaviors in PLC meetings based on the prompts. Furthermore, in interviews, participants explained that the prompts did have a positive impact on focusing meetings. The findings of this study might be of particular interest to professionals creating supports for teacher PLCs. [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.]