“…However, the responsibility for advancing a school's instructional capacity, historically borne by principals (Hallinger 2003, Barnett andAagaard 2007) is seen by many as simply too complex and overwhelming a job for a single leader given the myriad non-instructional issues that consume school leaders' attention (Portin 2000, Supovitz and Poglinco 2001, Fink and Resnick 2002, Fullan 2002, Gronn 2002, Lambert 2002, Resnick and Glennan 2002, Copland and Boatright 2006, Barnett and Aagaard 2007, Chrispeels et al 2008). These obstacles are often even more challenging for principals in urban high schools (Portin 2000, Resnick and Glennan 2002, Copland and Boatright 2006.…”