Schools often demonstrate limited capabilities to use and develop the organization’s collective competency. That’s why many international studies have pointed to an increased focus on the benefit of support structures to aid the professional work in local institutions (Elmore 2008; Stoll et al. 2006). Upper secondary schools have special challenges when it comes to developing the collective knowledge of the organization (McLaughlin & Talbert 2007). The size, the specialization and the bureaucratic organization lead teachers to work individually and what Hargreaves (1994) describes as being "balkanized” in subject departments. This paper draws upon findings from a study of a school improvement project where university experts cooperate with a group of teachers and the principal with the purpose of promoting writing in and across school subjects. Special attention is paid to how the teachers make use of their professional knowledge, and how they explore their practice connected to their work with student’s texts, and the influence of leadership. The paper aims to examine how professional knowledge is negotiated and developed in an interdisciplinary team of teachers, and how the school principal contributes to the teachers’ collective learning.

The approach takes into account that leadership is not necessarily synonymous with a particular position, and the leadership concept is closely related to a family of terms like authority, influence, and power (Gronn 2002). In an era of accountability in education and a greater focus on student outcomes and performance, there is a need to explore what supports the work of professionals in schools. Both school leaders and teachers are encouraged to reframe their understanding of their own practice. An approach to collective knowledge building that has been particularly significant in recent years has to do with the development of professional learning communities, a term that is related to the learning capacity of organizations (Vescio et al. 2008). The professional learning community is partly defined as a community "with the capacity to promote and sustain the learning of all professionals in the school community with the collective purpose of enhancing student learning" (Bolam et al. 2005, p.145). The importance of professional learning communities is linked to two central hypotheses: 1) that learning is situated and rooted in the daily activities in which teachers' collective reflection on own practice is central, and 2) that teachers who participate in these communities will enhance their professional competence, which turn will improve students' learning. The premise of the learning community is that students' learning is enhanced through increased teachers' learning (Stoll et al.2006).

[1] In Norway students in upper secondary schools are 16-18 years old.

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