This dissertation study includes an evaluation of a school district model of professional learning that aims to improve school administrators' instructional leadership skills and teacher practice to positively impact student learning. This study employs a valid and reliable survey instrument that measures professional learning standards. The narrow content focus of this model of professional learning is formative assessment practices. The findings of this study may inform policymakers, professional learning developers, and school districts interested in an effective model of school administrator and teacher professional learning. The design of this study is quantitative and a purposive convenience sample was sought. Participants include secondary school teachers (n = 281). This dissertation study includes descriptive and bivariate correlational statistics to determine the relationships among variables. [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.]