The question of how to promote teachers’ professional development has been discussed in various papers and research projects (e.g. Hargreaves, 2002; Sowder, 2007; Waters, Payler, & Jones, 2018; Zehetmeier, 2015; Zehetmeier, Potari, & Ribeiro, 2021). In this context, the question of impact is of particular relevance. Impact analyses and evaluations of professional development programmes are mainly scheduled during or at the end of a particular programme; they aim at and provide results regarding immediate and short-term effects. However, apart from and beyond that, an analysis of long-term and sustainable effects is crucial. This contribution provides information an Austrian nation-wide teacher professional development programme and gives insight into research regarding its impact. Here, the factors which foster or hinder the sustainability of impact are in particular focus. This professional development programme qualifies teachers to manage school development and quality development processes; its total duration is eight semesters. The programme combines individual professional learning and organisational development. Participants work on projects and initiatives carried out in their own respective schools. The programme is based on the following principles: instructional and school development are linked to each other; starting points are participants’ experiences, competencies, interests, and current developments at schools and in the Austrian school system; teachers take ownership of their learning process; equal emphasis is placed on a sound theoretical-methodological foundation and on experience learning from personal practice; the programme focuses on interconnection of classroom and school level. Concerning the programme’s impact, findings and results are based on data from various sources and time periods to gain validity by “convergence of evidence” (Yin, 2003, p. 100): data collection contained e.g. teachers’ project reports, archival records, and interviews. Data analysis included both inductive and deductive elements to analyse both the impact and the respective fostering (or hindering) factors. Data was analysed by qualitative content analysis (Mayring, 2003) in order to identify common topics, elaborate emerging categories, and gain deeper insight into teachers’ professional learning and development over time.

Hargreaves, A. (2002). Sustainability of educational change: the role of social geographies. Journal of Educational Change, 3, 189–214. Mayring, P. (2003). Qualitative Inhaltsanalyse [Qualitative content analysis]. Weinheim, Germany: Beltz. Sowder, J. (2007). The mathematical education and development of teachers. In F. Lester (Ed.), Second handbook of research on mathematics teaching and learning (pp. 157–223). Greenwich, CT: NCTM. Waters, J., Payler, J. & Jones, K. (2018). The Professional Development of Early Years Educators London: Routledge. Yin, R. (2003). Case study research: Design and methods (3rd Edition). Thousand Oaks, CA: Sage Publications. Zehetmeier, S. (2015). Sustaining and scaling up the impact of professional development programmes. ZDM - The International Journal on Mathematics Education, 47(1), 117-128. Zehetmeier, S., Potari, D. & Ribeiro, M. (2021). Professional Development and Knowledge of Mathematics Teachers. London: Routledge.