Typically, traditional professional development programs are characterized as “one shot” training workshops where experts deliver new knowledge or skills to teachers through lecture presentations. Furthermore, traditional professional development is usually not on-going and teachers do not gain feedback on their implementation of any new idea or skill. Given the limitations of traditional professional development, study groups have emerged as an alternative approach in which teachers have more autonomy to identify their own learning needs and to engage in self-directed learning. This book, therefore, examined the extent to which and the way in which Taiwanese educators in one selected high school in Taiwan viewed their English language study group as a form of staff development and professional learning community that contributes to their professional growth or learning. This book argued that the group provides a better form of professional development than traditional professional development activities because it was a teacher-directed activity in an informal format, and provided on-going opportunities to meet their needs.