Many investigators have documented the need for valid and credible program evaluation research of teacher professional development programs. Accordingly, the purpose of this study was to conduct a comprehensive program evaluation of the Lincoln School District's Teacher Collaboration Time (TCT) staff development program. The study questions explored the TCT program's merit and worth. It examined the internal evaluator's role and experiences throughout the evaluation process. Designed as a mixed-method study, the program evaluation framework focused on three types of investigative inquiry: formative, summative, and meta-evaluation. Formative measures addressed program merit, identifying to what extent current TCT practices align to the National Staff Development Standards put forth by the National Staff Development Council. A summative investigation analyzed multiple years of the No Child Left Behind (NCLB) student achievement score data, for the purpose of determining TCT's level of impact and program worth. Throughout the process, the evaluator engaged in meta-evaluation of one's role as an internal evaluator notably, the challenges and difficulties encountered. The convergence of multiple formative datasets provided authentic evidence to reliably validate TCT's merit. The summative results, however, do not support a conclusion that the TCT program produced significant gains in student achievement (program worth). This study is instructive in how an internal evaluator can credibly conduct a comprehensive program evaluation in his or her own workplace. The program evaluation framework serves as a model for school districts to assess current staff development practices, engage in reflective dialogue, develop an action plan for improving staff development, and thereby enact social change and organizational reform. [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.]