Conference Program

Teachers’ working conditions are increasingly recognised as a key factor shaping the effectiveness of education systems, as well as students’ learning outcomes and educational inequalities (Hanushek & Rivkin 2012; OECD 2025). While a large body of research has examined institutional features of school systems, growing attention is now being devoted to teachers’ working conditions, professional well-being, and perceived effectiveness (Darling-Hammond 2017). Understanding how teachers interpret the challenges of everyday teaching is crucial for analysing how educational policies and school structures are translated into practice.

Student heterogeneity is a structural feature of contemporary classrooms, encompassing differences in socio-economic background, language, learning needs, and educational trajectories. In Italy, recent policy developments — such as legislation on learning disorders (L. 170/2010) and the extension of the category of Special Educational Needs — have increased institutional attention to diversity in schools, making the management of heterogeneous classrooms a core component of teachers’ professional role. At the same time, research and policy debates often address diversity through specific categories of students rather than considering heterogeneity as a systemic condition of everyday teaching (Ianes et al. 2020).

This paper investigates how classroom composition and organizational conditions shape teachers’ expectations of professional stress and teaching effectiveness. The analysis draws on data from a large survey of Italian teachers (N ≈ 9,500) that includes a factorial survey experiment. Respondents were presented with vignettes describing hypothetical classroom compositions varying across several dimensions: class size (18 vs 24 students), gender composition, presence of students with migrant background, presence of students with specific learning disorders (SLD), and level of family collaboration. In a second stage, an additional organizational factor was introduced: the composition of the teaching staff, distinguishing between classes with a stable teaching team (mostly tenured teachers) and classes with a high presence of substitute teachers. Teachers were asked to evaluate how stressful teaching in the described class would be and how effective they expected their teaching to be.

Results show that teachers generally report moderate expected stress and relatively high confidence in their teaching effectiveness, which aligns with previous research highlighting the cumulative nature of risk and protective factors shaping teachers’ well-being (Zagni et al. 2025). However, both outcomes are significantly shaped by structural and organizational conditions. Larger classes, low family collaboration and instability in the teaching staff substantially increase expected stress and reduce perceived teaching effectiveness. In several cases, organizational features such as the stability of the teaching staff appear to have an impact comparable to, or greater than, the characteristics of students themselves.

These findings suggest that teachers’ professional experience cannot be fully understood by focusing only on student diversity. Instead, the organizational environment in which teachers work plays a crucial role in shaping both professional well-being and expectations of effectiveness. By highlighting the interaction between classroom heterogeneity and school organizational conditions, the paper contributes to current debates on teachers’ working conditions and their implications for school effectiveness and educational inequalities.