Methodological and Contextual Trends of Teacher Leadership and its Conceptualization: A Systematic Literature Review (2018-2022)

Despite decades of research on teacher leadership, its definition remains marked by significant conceptual and operational disagreements. To systematically update the latest developments and research trends in this field, this literature review employed the Scopus and ScienceDirect databases to analyze 80 empirical studies published between 2018 and 2022 that met predefined criteria. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) screening procedure, a detailed examination was conducted on the research contexts, methodological approaches, and definitions of teacher leadership. The findings revealed that the overall growth rate has been relatively slow between 2018 and 2022, with most studies utilizing qualitative research methods. Currently, teacher leadership research focuses primarily on K-12 teacher populations in North America and Asia. Notably, teacher leadership is conceptualized as a complex and multidimensional construct, and its definitions remain conceptual and operationally unharmonized, influenced mainly by the specific context and school culture of each study.