“…Teacher leadership is regarded as an important factor in school development and effectiveness, as well as the dissemination of democratic values (Donaldson, 2006;Frost & Durrant, 2003;Poekert, 2012;Wenner & Campbell, 2016;York-Barr & Duke, 2004), the formation of common values, teacher effectiveness and collaboration (Harris & Muijs, 2005), administrator support (Hobson & Moss, 2010), and improvement in the quality of education (Danielson, 2006;Gehrke, 1991;Kılınç, 2014;Poekert, 2012;Wenner & Campbell, 2016). The concept of teacher leadership refers to teachers' behaviors related to institutional development, professional development and collaboration with colleagues (Beycioğlu, 2009), and their knowledge, skills and behaviors for improving learning and instruction at school (Harris & Muijs, 2005).…”