The purpose of this qualitative study was to explore the perceptions of what makes a collaborative learning team (CLT) effective for novice and experienced teachers. Professional learning communities have emerged as one approach for job-embedded professional learning so that teachers have the opportunity to collaborate with the end goal of improving their teaching practices as well as promote continuous school improvement. To explore these issues, the research questions that guided this study included: How do CLTs influence middle school math teachers to explore the nature of the mathematics content and pedagogy? What are the perceptions of novice teachers in terms of effective components of their CLT? What are the perceptions of experienced teachers in terms of effective components of their CLT? How does teaching experience influence perception for effective CLTs? Qualitative data were collected through three interviews from four novice and three experienced middle school math teachers in two different middle schools in the mid-Atlantic. The school sites were selected because teachers participated in regularly scheduled CLT meeting. Five factors were found that contributed to a successful and effective CLT: (1) the logistics and structure of the meeting must match teachers' schedules (with only one content focus); (2) there was flexibility within the meeting to support the needs of the teachers on the team; (3) there was shared responsibility and shared learning which is a part of the collective expertise among the participants on the CLT team; (4) there was a sense of belonging and community that influenced their work to be more enjoyable; and (5) the meeting content directly related to what is happening in teachers' classrooms. These five factors represented what participants in this study perceived as contributing to effective work within their CLT. When these features were present and incorporated into the work of a CLT, the team had better opportunities for both teaching and learning mathematics. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]