This study aims to examine how collaborative action research has contributed to a teacher’s professional development. It built a framework from the teacher identity perspective, aimed at deriving further insight into the effects of collaborative action research as a professional development program. It is a case study of a Korean primary school English teacher who conducted collaborative action research to improve the quality of teaching English writing. The qualitative data were collected from teaching logs, written accounts and semi-structured interviews, then analysed. The study found that the teacher experienced growth in teacher identity based on his capacity building through collaborative action research. The factors affecting the growth of teacher identity are positive attitudes to address vulnerability in teaching English, participation in the collaborative action research, continuous reflection and establishing ownership during the research. Theoretically, this study suggests the development of teacher identity perspective and its application to design, execute and evaluate teacher education programs for in-depth understanding. Practically, it provides implications for English teacher education.

Abstract
I. INTRODUCTION
II. THEORETICAL BACKGROUND
III. RESEARCH METHODS
IV. FINDINGS AND DISCUSSIONS
V. CONCLUSION
REFERENCES

• Hyoshin Lee(Institute of Education, University of London)