Collaboration between teachers is considered in general as a key characteristic of school effectiveness and a crucial factor for school improvement (Kyriakides et al., 2010). Therefore, teacher collaboration is included in systematic models of school quality as a feature of process quality on school level (Ditton, 2000). Several international research findings prove that teacher collaboration has positive influences on teachers’ work life, e.g. coping with stress and professional development, as well as on teaching quality and students’ academic achievement (Fussangel & Gräsel, 2011; Steinert et al., 2006). In addition, teacher collaboration plays an important role for school development by building up shared goals, consensus and cohesion in teaching staff (Holtappels, 2013). But it is also evident, that teacher collaboration itself is positively influenced by features of teachers, e.g. self-efficacy, as well as cultural and organizational features of schools, e.g. working climate, institutionalized teams, instructional leadership (Vangrieken et al., 2015).

In particular effective schools confronted with challenging circumstances are characterized by professional learning communities, where teachers work together to develop their professional knowledge and improve their teaching practices to support students' learning (Muijs et al., 2004). However, especially schools in challenging circumstances do not only suffer from external problems, but also from internal difficulties, which hinder teacher collaboration instead of facilitating it, e.g. high rates of absenteeism (Harris & Chapman, 2004). Although many studies concerning teacher collaboration are available, the research findings are barely generalizable and comparable, because reviewing the literature teacher collaboration is often used as an umbrella term and conceptualized and operationalized diversely (Ahlgrimm et al., 2012; Kelchtermans, 2006). This is mostly due to the fact that teacher collaboration does not only occur with a different intensity, but also takes on different forms in school reality.

Based on an organizational psychological definition, which describes collaboration as a certain form of social interaction characterized by common goals and tasks, mutual trust and autonomy (Spieß, 2004), Gräsel et al. (2006) distinguish three forms of teacher collaboration: 1. exchange of work-related information and materials, 2. division of work and 3. co-construction of joint knowledge. All forms focus on instruction, but vary in their requirements and functions for teachers’ every day work, professional and instructional development. While exchange conduces to spread relevant or helpful information and materials in teaching staff, division of work enhances efficiency of every day work and co-construction extends professional development of teachers and improvement of teaching quality by observations and feedbacks with colleagues. From the first to the last form of teacher collaboration individual and organizational requirements rise: The bond to common goals and tasks becomes more extensive, interdependent and long-term, mutual trust between cooperation partners increases, whereas their autonomy decreases. That is why the first form is referred to as low-cost and the last as high-cost form of teacher collaboration (cf. ibid.). As a result – across different school types of primary and secondary schools – teachers realize high demanding forms of collaboration less often than low demanding forms (Harazd & Drossel, 2011).

Referring to the presented differentiation of teacher collaboration the main objective of the paper is twofold: First, teacher and school features, which affect the different forms of collaboration, are examined. Second, the impact of different forms of collaboration on instructional development is investigated. The paper follows three research questions:

1. How often do teachers realize each form of teacher collaboration in their everyday work?

2. Can specific individual, structural and cultural conditions of each form of teacher collaboration be found?

3. Can differential effects of each form of teacher collaboration on different activities of instructional development be identified?

Ahlgrimm, F., Krey, J. & Huber, S. G. (2012). Kooperation - Was ist das? Implikationen unterschiedlicher Begriffsverständnisse. In Stephan G. Huber & F. Ahlgrimm (Hrsg.), Kooperation: Aktuelle Forschung zur Kooperation in und zwischen Schulen sowie mit anderen Partnern (S. 17–29). Münster: Waxmann. Ditton, H. (2000). Qualitätskontrolle und Qualitätssicherung in Schule und Unterricht. Ein Überblick zum Stand der empirischen Forschung. In A. Helmke, W. Hornstein & E. Terhart (Hrsg.), Qualität und Qualitätssicherung im Bildungsbereich: Schule, Sozialpädagogik, Hochschule (41. Beiheft der Zeitschrift für Pädagogik, S. 73–92). Weinheim: Beltz Verlag. Fussangel, K. & Gräsel, C. (2011). Forschung zur Kooperation im Lehrerberuf. In E. Terhart, H. Bennewitz & M. Rothland (Hrsg.), Handbuch der Forschung zum Lehrerberuf (S. 667–682). Münster: Waxmann. Gräsel, C., Fussangel, K. & Pröbstel, C. H. (2006). Lehrkräfte zur Kooperation anregen – eine Aufgabe für Sisyphos? Zeitschrift für Pädagogik, 52 (2), 205–219. Harazd, B. & Drossel, K. (2011). Formen der Lehrerkooperation und ihre schulischen Bedingungen – Empirische Untersuchung zur kollegialen Zusammenarbeit und Schulleitungshandeln. Empirische Pädagogik, 25 (2), 145–160. Harris, A. & Chapman, C. (2004). Improving schools in difficult contexts: towards a differentiated approach. British Journal of Educational Studies, 52 (4), 417–431. Holtappels, H. G. (2013). Schulentwicklung und Lehrerkooperation. In N. McElvany & H. G. Holtappels (Hrsg.), Empirische Bildungsforschung. Theorien, Methoden, Befunde und Perspektiven (S. 35–61). Münster: Waxmann. Kelchtermans, G. (2006). Teacher collaboration and collegiality as workplace conditions. A review. Zeitschrift für Pädagogik, 52 (2), 220–237. Kyriakides, L., Creemers, B., Antoniou, P. & Demetriou, D. (2010). A synthesis of studies searching for school factors: implications for theory and research. British Educational Research Journal, 36 (5), 807–830. Muijs, D., Harris, A., Chapman, C., Stoll, L. & Russ, J. (2004). Improving Schools in Socioeconomically Disadvantaged Areas – A Review of Research Evidence. School Effectiveness and School Improvement, 15 (2), 149–175. Spieß, E. (2004). Kooperation und Konflikt. In H. Schuler (Hrsg.), Organisationspsychologie – Gruppe und Organisation (Enzyklopädie der Psychologie, Themenbereich D, Serie III, Band 4, S. 193-250). Göttingen: Hogrefe Verlag für Psychologie. Steinert, B., Klieme, E., Maag-Merki, K., Döbrich, P., Halbheer, U. & Kunz, A. (2006). Lehrerkooperation in der Schule: Konzeption, Erfassung, Ergebnisse. Zeitschrift für Pädagogik, 52 (2), 185–204. Vangrieken, K., Dochy, F., Raes, E. & Kyndt, E. (2015). Teacher collaboration: A systematic review. Educational Research Review, 15 (2), 17-40.