As education policy makers around the world sharpen their focus on teacher quality as a key lever on student acheivement, teacher education becomes more and more the object of review and reform (Hattie, 2008; OECD, 2005; Sahlberg, 2012; Sanders & Horn, 1998; Sleeter, 2009). In some countries (the UK and the USA in particular) there is a turn towards situating teacher education as close as possible to practice in authentic settings in order to increase its effectiveness (Korthagen & Kessels, 2010; Zeichner, 2012).

This paper reports on a study that is part of a programme of research into how teacher education can prepare teachers who can make a difference for learners. A fundamental premise underlying the work is that the ultimate goal of initial teacher education, as a values-oriented professional enterprise, is to prepare teachers who engage in patterns of practice that promote and support the academic, social, emotional, civic, and critical learning of all students, including, and especially, those who have traditionally been marginalized and not well served by the education system.

The study was conducted within a theoretical framework that allies complexity theory with critical realism (CT-CR) (Cochran-Smith, Ell, Ludlow, Grudnoff & Aitken, 2014). CT-CR rejects linear models of cause and effect, but believes that explanatory theories can be developed by carefully investigating multiple, contingent causality (Byrne, 1998; Reed & Harvey, 1992). CT-CR uses the term ‘causal mechanisms’ to express this non-linear and multi-factorial notion of how things come to be. In this framework learning to teach in ways that improve outcomes for all students occurs within intersecting complex systems, where the effects of particular actions or interactions are non-random but not predictable and may be amplified or diminshed in unexpected ways. CT-CR asserts that, in teacher education, what we do does make a difference, but that we cannot draw straight lines between particular arrangements, pedagogies or content and the teaching effectiveness of graduates. We need to pay attention to the interactions between the many components of teacher preparation, as well as to the components themselves (Cochran-Smith & Zeichner, 2005; Grossman & McDonald, 2008; Opfer & Pedder, 2012).

To begin investigating how people learn to teach in ways that improve student outcomes, a rich, concrete description of teacher education that provides an analysis of the significant components of teacher education and the relationships between them is needed (Danermark, Ekstrom, Jakobsen, & Karlsson, 1997). CT-CR suggests that people in different parts of the teacher education system will perceive its functioning in different ways, seeing parts of the system clearly while not understanding the overall system’s functioning. Thus the research question for this study was: What do the various participants (i.e., teacher candidates, school-based teacher mentors, university-based teacher educators, and policy makers) in a complex initial teacher education system perceive to be the key elements in that system that promote teacher candidates’ learning to teach in ways that promote children's learning?

Aldenderfer, M.S. & Blashfield, R.K. (1984). Cluster analysis. Sage University Paper series, no. 44. Beverly Hills; Sage Publications. Byrne, D. (1998). Complexity Theory and the Social Sciences. London and New York: Routledge Cochran-Smith, M., Ell, F., Ludlow, L., Grudnoff, L., & Aitken, G. (2014). The challenge and promise of complexity theory for teacher education research. Teachers College Record. 116(6). Cochran-Smith, M., & Zeichner, K. (2005). Studying Teacher Education: The Report of the AERA Panel on Research and Teacher Education. Mahwah, N.J.: Lawrence Erlbaum Associates. Danermark, B., Ekstrom, M., Jakobsen, L., & Karlsson, J. (1997). Explaining society: Critical realism in the social sciences. London: Routledge. Everitt, B. (1974). Cluster analysis. London: Heineman Educational Books Grossman, P., & McDonald, M. (2008). Back to the Future: Directions for Research in Teaching and Teacher Education. American Educational Research Journal, 45(1), 184-205. Hattie, J. (2008). Visible learning. Routledge: London Korthagen, F. & Kessels, J. (2010). Linking theory and practice: Changing the pedagogy of teacher education. Educational Researcher, 28 (4), pp. 4-17 Opfer, V. D., & Pedder, D. (2011). Conceptualizing Teacher Professional Learning. Review of Educational Research, 81(3), 376-407. Organization for Economic Cooperation and Development (2005). Teachers Matter: Attracting, Developing and Retaining Effective Teachers. Paris. Reed, M & Harvey, D.L.(1992). The new science and the old: Complexity and realism in the social sciences. Journal for the Theory of Social Behaviour, 22(4), 353-380. Sanders, W., & Horn, S. (1998). Research findings from the Tennessee Value-Added Assessment System (TVAAS) database: Implications for educational evaluation and research. Journal of Personnel Evaluation in Education, 12(3), 247-256. Zeichner, K. (2012). The turn once again toward practice based teacher education. Journal of Teacher Education, 63 (5), pp. 376-382