The co-teaching model is a system that has been designed to incorporate the use of more than one teacher in the classroom. As the use of co-teaching has become more prevalent in the educational system, it has proven to be beneficial to pre-service teachers (PSTs) and in-service teachers alike. Providing a framework that focuses each pre-service teacher's (PST's) school clinical observation time on working side by side with experienced educators, increases the effectiveness of PST's time in the field. The co-teaching model elicits active participation and collaboration with the more experienced in-service teacher, resulting in better clinical outcomes. Another beneficiary of the positive attributes of the co-teaching models is the in-service teacher. Co-teaching reduces the teacher-to-student ratio helping each teacher have the opportunity to spend time more quality with individual students. Professional development schools (PDS) provide a living teaching and learning laboratory allowing teacher candidates to work with experienced classroom mentors as they practice and refine their pedagogical skills.