Teacher use of formative assessment is lacking worldwide despite evidence supporting its potential for improving student outcomes. To address a local problem of formative assessment implementation, Franklin County School's professional development team designed and implemented a yearlong program to improve teacher knowledge and practice of formative assessment. Utilizing secondary survey data, I evaluated the program by determining the extent to which teaching level, engagement with professional development, and perceived effectiveness predicted changes in outcomes. Quantitative analysis revealed marginal programmatic effects on teacher knowledge and practice of formative assessment. Assessed program variables were unable to predict changes in teacher belief. Following the analysis, I offer several recommendations for practice. For instance, professional development efforts should align learning activities to standards for professional learning to ensure quality and consistency, and evaluators should aim to collect data on specific actions rather than rely on data in aggregate. Likewise, increasing the quality of professional development activities and the time teachers spend engaged in learning may positively impact outcomes. Leaders could also implement job-embedded learning processes that further encourage professional experimentation and motivate teachers to persist through the challenge of change. Finally, program leaders should consider contextual factors influencing outcomes when designing and implementing programs. In addition to the provided context-specific recommendations, this evaluation adds to the literature on teacher change by validating Guskey's (1986, 2002) linear model and Clarke and Hollingsworth's (2002) Interconnected Model, which hold that changes in teachers' beliefs do not precede changes to their practice. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]