This study investigated the effect of two models of professional development concerning Assessment for Learning on teacher perception of the effectiveness of Assessment for Learning strategies and student achievement as measured by standardized Georgia End of Course Tests. The study hypothesized that a positive relationship exists between teacher perception of the benefit of Assessment for Learning strategies and increased student achievement as measured by student performance on standardized Georgia End of Course Tests. The study hypothesized that a positive relationship exists between teacher participation in Assessment for Learning professional development and teacher positive perception of the benefit of Assessment for Learning strategies. The sample consisted of 174 teachers and 2,787 students in core content courses in grades 9-12 in rural Georgia schools. Teacher participants received training on Assessment for Learning in either a theory-based or application-based professional development class or were part of the control group not participating in Assessment for Learning professional development. Teacher participants completed a detailed survey to gather assessment perception data. Students participated in instruction and completed Georgia End of Course Tests (EOCT), standardized achievement assessments, to gather performance data. Multiple ANOVA were used to statistically analyze the data and a relationship was found between teacher participation in formative-assessment professional development and student performance on standardized Georgia End of Course Tests. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]