A problem exists in the U.S. education system regarding the efforts to refine professional development and gain a deeper understanding of content knowledge to impact teachers' abilities to meet students' needs. Many teachers have not had the professional development opportunities that support the improvement of teaching skills and knowledge. The purpose of study was to examine the relationship of professional development to teacher and collaborative efficacy. The perceptions of Title I middle school teachers facing No Child Left Behind (NCLB) school reform were interpreted through the collected data. Theoretical foundations focused on Bandura's social cognitive theory, adult learning, and transformational change theory. A descriptive mixed method concurrent nested design was used with the independent variable being professional development and the dependent variable being levels of teacher efficacy and perceived collaboration efforts in professional development venues. Quantitative and qualitative data were derived from responses to an adapted Professional Development Survey Questionnaire administered one time to a convenience sample of teacher participants. Qualitative data included development agendas, site monitoring and school improvement reports. Pearson correlation and ANOVA were used to analyze the quantitative data and qualitative data were content analyzed concurrently. Findings included teacher self-efficacy being strengthened by professional development collaborative activities and that participants related these professional development experiences to increased student outcomes. The positive social change implications included opportunity for research based policy changes that impact professional development for teachers to aid in their endeavors to raise achievement levels and to meet NCLB mandates. [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.]