This dissertation, "Teacher Learning in Communities of Practice: Improving Teaching Through Analysis of Classroom Videos" by Fei-yin, Lo, 盧飛燕, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Due to the new demands placed upon schools in our current learning society, teachers are expected to learn continuously. However, not much is known about how teachers learn. Three major problems are identified in the emerging literature. First, little is known about what constitutes meaningful learning from the teachers' own perspectives. Second, there is a lack of a common framework for analysing and comparing findings across different studies on the process of teacher learning. This is a major obstacle in advancing the field. Third, factors affecting teacher learning are often studied in an isolated manner without acknowledging the interaction among these factors. As a result, this fails to provide a holistic picture of how teacher learning can be enhanced or impeded. In view of the above, this study adopted a teacher perspective to investigate teacher learning and the factors affecting it in a holistic manner, using an interpretive framework that can be applied across different studies. The study was situated in the context of a year-long school-based teacher professional development (TPD) programme. Seven teachers of two different schools participated in the study. Teachers in each school formed a community of practice that made use of classroom videos to improve their practice. A case study approach was used to document the content and process of teacher learning, as well as to illuminate how various factors interact to affect teacher learning within the two communities. Data was collected from individual teacher interviews, teacher reflection tasks, discussion in the TPD meetings and non-participant observation. The Interconnected Model of Teacher Professional Growth (IMTPG) and Community of Practice (CoP) were adopted as the interpretative frameworks for data analysis. Besides gaining knowledge and skills, the teachers also exhibited affective and social learning. More than half of the teachers considered affective learning (e.g., confidence in their own identity as a good teacher)and social learning (e.g., building a trusting relationship with colleagues) as the most important learning to them. The idiosyncratic and recursive nature of teacher learning is consistent with existing literature. Three types of factors that have a bearing on teacher learning were identified. First, the individual factors, which include the teacher's will to learn, level of reflectivity and time available for professional development. Second, the communal factors, which include: (i) the ways in which members in a CoP engage with each other (i.e., engagement), (ii) the ways in which members construct an image of themselves (i.e., imagination), and (iii) the ways in which members coordinate perspectives, interpretations, and actions so that the CoP can realise higher goals (i.e., alignment). Third, the features of the TPD programme that were reported by teachers as helpful in facilitating their learning, including the multiple strategies adopted, videos, and facilitation from a university educator. Implications for video-based TPD and for research on teacher learning were identified, in particular, a need for more research on teacher learning from the teachers' own perspective in order to better understand teachers' authentic learning experiences and to build a more holistic model of teacher learning. DOI: 10.53