The advent of technology brings computational thinking (CT) to educators’ attention. Countries all around the world have been updating their computer science (CS) curricula so that students can acquire computational thinking skills. The Massachusetts Department of Elementary and Secondary Education has recently updated its Digital Literacy and Computer Science frameworks (DLCS) to integrate CT concepts. This dissertation focuses on analyzing one NSF-funded effort, the CS-for-All Springfield Research-Practice Partnership (RPP), which has made efforts to integrate CS/CT professional development, towards designing and implementing CT curriculum in K-5 schools. Important aspects when analyzing the effectiveness of new curriculum implementation are: how in-service teachers are prepared to implement the integrated CS/CT curriculum, how they apply suitable pedagogy aligned with computational thinking skills, and how the implementation of the curriculum influences their Technology and Pedagogical Knowledge of Computational Thinking (TPACK-CT). This study examines how participation in the CS for All RPP Springfield project influenced K- 5 grade in-service teachers' TPACK for CT. In order to find answers to these questions, a TPACK-CT survey and semi-structured interviews were conducted with teachers within both experimental (Cohort A) and control groups (Cohort B and C). Surveys were administered, consisting of two main parts. In the first part, teachers were asked to achieve some demographic information; in the second part, 22 Likert-type items assessed their TPACK for computational thinking. In addition, ten (10) teachers from Cohort A were selected to be interviewed to enrich the data source and to help interpret quantitative results. During the interviews, teachers were asked how attending the CT Professional Development sessions, implementing the CS/CT curriculum, and participating in a community of practice (the school-based CT professional learning community) helped them develop their TPACK for CT. These results should inform the development of future high-quality professional development sessions, which are connected to in-service teachers' practice as well as help them improve their TPACK for CT. @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-536870145 1107305727 0 0 415 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0in; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman",serif; mso-fareast-font-family:"Times New Roman";}.MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-font-kerning:0pt; mso-ligatures:none;}div.WordSection1 {page:WordSection1;}