Focus of Inquiry This paper identifies patterns of critical influences on teachers’ sense of commitment and resilience over the course of their professional lives, in order to understand if teachers become more effective over time: if so, why and if not, why not. The key research questions therefore are: i) Does teacher effectiveness vary from one year to another, and in terms of different pupil outcomes? ii) Do teachers necessarily become more effective over time? If so, how and why? iii) What are the roles of teacher biography and identity? Background The data for this paper are drawn from the VITAE research (Day et al., 2007) on the span of teachers’ professional lives. This research investigated teachers’ work, lives and effectiveness (perceived by teachers and measured by ‘value added’ test scores) from a holistic perspective. This perspective provided richer insights into the complex and dynamic nature of the conditions for teachers’ effectiveness throughout their professional lives than previous research, which has focused upon one or other of the conditions and influences on teachers, has been able to do. The VITAE research extended Huberman’s (1993) seminal study of the lives of Swiss secondary school teachers and those of English teachers by Sikes et al. (1985) and of US teachers by Fessler and Christensen (1992). However, these studies did not address the influences on teachers’ work, lives and perceived effectiveness in their different personal and school contexts across time, nor did they explore relationships between these and what, if any, effect they have on pupil learning and achievement. Theoretical Frame The concept of critical influences reveals teachers’ primary concerns and differing needs in different phases of their professional and personal lives. The positive/negative impact of critical influences on teachers’ perceived effectiveness indicates the extent to which teachers’ primary concerns are recognised and differential needs for development are satisfied and how far this is/is not achieved. The VITAE research found that in order to understand variations in teachers’ work and lives, one has to understand variations in the impact of these critical influences on teachers’ feelings of being an effective teacher, needs for professional development, and tensions in managing and sustaining a healthy work-life balance over the course of their professional lives.

Research Methods Data on critical influences were collected through narrative interviews with 300 teachers in 100 primary and secondary school who were participants in the four-year multi-method VITAE research project. Teachers were asked to construct a timeline indicating critical influences on their effectiveness over their career histories as perceived by themselves. They recalled turning points in their professional and personal lives which were key moments and experiences that had had a significantly positive or negative impact on their effectiveness as perceived by teachers themselves and/or measured by ‘value added’ pupil attainment data as defined by national tests at Key Stage 1, 2, and 3.

Key critical influences were found to consist of three dimensions: situated factors (related to their lives in school), professional factors (related to their values, beliefs and the interaction between these and external policy agendas) and personal factors (related to their lives outside school). These dimensions were not static. The capacity to manage the interaction between these was key to teachers’ abilities to sustain their commitment and effectiveness, that is, to be resilient. The ‘critical influences’ research has revealed that it is the relative intensity of various factors that influence differentially on teachers’ work in different phases of their professional lives, and that it is how teachers manage and are supported in managing these influences which affects their capacity to sustain their effectiveness.