Literature has shown that professional development is most effective when it is ongoing, involves active, collective participation, and has coherence with the overall curriculum and teacher experience. This study was designed to examine the manner and extent to which Jamestown Polytechnic Charter School Organization designs and implements effective professional development to promote the transfer of 21st Century skills into classroom practice while maintaining high achievement on state accountability measures such as the CST's. Not only is JPCSO implementing professional development on 21st century skills that transfers to teacher practice, the organization has redefined how to promote the development of these skills, by embedding 21st century skills into the practices of the organization and the activities of professional developments. While the findings do support the literature on effective professional development, three main factors emerged as critical to JPCSO's success: culture of collaboration, professional transparency, and skills-embedded professional development and professional practice. Furthermore, the organization, through its use of college-going indicators, has redefined teacher effectiveness and student achievement. Jamestown Polytechnic's practices, coupled with their success, has powerful implications for the way stakeholders design professional development and measure the effectiveness of school organizations; ultimately, leading education down a path that emphasizes high levels of student achievement beyond the K-12 system to understand the extent to which students are actually prepared for global participation in the 21st century. [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.]