The Institute for Teaching and School Development at the University of Klagenfurt follows, among other things, an empirical and analytical approach to research in existing learning environments.  The research project presented here, which is being carried out as part of a dissertation at this very institute, follows this approach. The focus is on a form of organisation at the primary level that is unique in Europe: teaching children from first to sixth grade in a mixed-age class based on the Montessori concept. With their interdisciplinary, non-frontal, grade- and exam-free setting, in which standardized textbooks are not used (Eilers 2018), these primary classes represent a stark contrast to the familiar framework conditions of teaching and schooling.

Mixed-age groups in educational settings take various forms in Europe but are most common in early childhood education or in the first years of school. (Wagener, 2022) In addition, it has been and continues to be used as an organisational solution for primary schools in rural areas in order to maintain them despite low student numbers. (ibid.) Although some international research has now been published on multi-level work in primary schools, which can be implemented in a wide variety of ways (ibid.), classes with six age groups working according to the Montessori concept remain a research desideratum.

Since this is a new exploration of a rarely implemented and scientifically untouched learning environment and thus an “unusual case” (Yin, 2018, p. 50) case study research (Yin, 2018) was selected for the dissertation project combined with Constructive Grounded Theory (Charmaz, 2014). The study uses a multiple-case study design to examine two classes, one located in Germany and the other in Austria. Both classes are embedded in privately run schools that provide education leading to the completion of compulsory schooling.

While previous studies on multi-age classes have highlighted findings in areas such as children's social development (Harrison, 2018), mutual assistance (Wagener, 2022) or participatory practices in learning interactions in mixed-age tandems (Wagener & Walther, 2024), the research project presented here aims to holistically capture the specifics of the reception, transmission, and reproduction of knowledge in the classes studied. The guiding research questions address the classroom culture enacted in the classes, how knowledge is acquired, reproduced, and transmitted, and which perspectives on and approaches to knowledge can be identified. In line with common practice in Constructive Grounded Theory, the theoretical framework is developed as Sensitizing Concepts (cf. Keane and Thornberg 2025, p. 121) and includes perspectives from Dave Elder-Vass (2012), Käthe Meyer-Drawe (2012), and Wolfgang Maiers (2017).

From an ethical standpoint, the present project adheres to the International Charter for Ethical Research Involving Children, and the “Getting Started” reflection questions from the Ethical Research Involving Children platform were applied (Graham et al. 2024). Moreover, the author aims to contribute to a critical and constructive perspective on developments within the Montessori concept, which is implemented in schools worldwide irrespective of national school laws and curricula (Murray, 2022). Recent publications (see, among others, Hopmann 2022; Canzoneri-Golden und King 2023; Seichter 2024 and Seichter 2025) highlight pedagogical blind spots and their implications for learners, which this research project explicitly addresses and discusses.

A Case Study Research design was chosen within Yin's second strategy, “working data from the ground up” (Yin, 2018, p. 169). Within this strategy, Constructive Grounded Theory (Charmaz, 2014) forms the framework according to which the data is processed and analysed. The data for the study was collected during fieldwork in 2021, 2025 and 2026. The criteria for case selection were the duration of the extended age mix (at least three already completed graduate cohorts), the existence of upper secondary education within the same organisation, the school's interest in participating in the research and a good access to the field. In line with Yin’s concept of convergence of evidence, data were collected using a multi-perspective approach. Such approaches are recommended in both case study research (Yin, 2018) and studies on children’s perspectives (Nentwig-Gesemann, 2024; Velten et al., 2018; Vogl et al., 2023), and are considered a forward-thinking development within the context of Constructive Grounded Theory (Keane and Thornberg 2025). Focus groups with both the children and the teachers served as one of the research tools. In addition, children from the sixth grade were invited to write texts about their time in primary school. Observation was chosen as the third approach, not least to explore social phenomena that are physical, performative, nonverbal, and can be observed in situ. As a supplement to the observation, artifacts and photos were included in the data. Throughout the research, memos (Charmaz 2014; Keane and Thornberg 2025) were the central element of analytical notes. Before presenting the theoretical concepts developed as part of the emerging Grounded Theory, case study reports for each case (Yin, 2018) were compiled as intermediate steps and subsequently reflected upon through a cross-case analysis.

As the study is still in progress, the following statements are based on expected results. The dynamics between older and younger children shape the patterns of interpretation and courses of action that emerge in relation to knowledge. The visible diversity of developmental stages structures the progression of knowledge and skills while simultaneously fostering responsibility, role-modelling, and inspiration within both classes. Knowledge and its transfer are treated as a form of collective property; it is jointly created, tested, and shared. A central sequence of processes concerning the acquisition, transfer, and reproduction of knowledge has been identified. These steps and actions, repeatedly enacted by teachers and children, are constitutive of the learning process. In this context, active engagement—or, in the participants’ own words, “working”—is central to knowledge construction. The observed forms of work and the range of possible student activities are highly diverse, which is also reflected in the teachers’ interpretative patterns regarding students’ “ownership” of their learning processes. Interest, motivation and energy emerge as key conditions for knowledge acquisition, while the establishment of relationships—both among actors and with topics or subject areas—constitutes a fundamental component in both classes. Another particularly notable aspect is the permeability of the classrooms promoted by the teachers, which decentralizes knowledge power and opens the socio-economic environment of the schools to the students as a basis for learning. Moreover, the reduction of strong external synchronization in the absorption, reproduction, and transmission of knowledge plays an important role.

Charmaz, K. (2014). Constructing Grounded Theory (2nd ed.). SAGE Publications, Inc. Harrison, K. (2018). Age de-segrated Learning Environments in Elementary Schools [Dissertation]. St. John's University, New York. Murray, A. (2022). Global Montessori Census 2022. https://public.tableau.com/app/profile/angela.murray/viz/GlobalMontessoriCensus2022/MontessoriCensusMap Nentwig-Gesemann, I. (2024). Herausforderungen und Methoden der Erforschung von Kinderperspektiven im Rahmen der Kindheitsforschung. In A. Schierbaum, M. Diederichs, & K. Schierbaum (Eds.), Kinder, Kindheiten und Kindheitsforschung: Band 30. Kind(er) und Kindheit(en) im Blick der Forschung: Zentrale theoretische Figuren und ihre empirische Erkundung (Vol. 30, pp. 225–242). Springer VS. https://doi.org/10.1007/978-3-658-42625-5_13 Velten, K., Alexi, S., & Höke, J. (2018). Die Erfassung von Kinderperspektiven und ihr Potenzial für Forschung und Professionalisierung. In Miller, S. et al. (Ed.), Jahrbuch Gundschulforschung: Profession und Disziplin (pp. 127–137). Springer Fachmedien. Vogl, S., Schmidt, E.‑M., & Kapella, O. (2023). Focus Groups With Children: Practicalities and Methodological Insights. Advance online publication. https://doi.org/10.17169/FQS-24.2.3971 Wagener, M. (2022). Jahrgangsübergreifender Unterricht: Didaktische Grundlagen und Konzepte (1. Auflage). Verlag W. Kohlhammer. https://doi.org/10.17433/978-3-17-035265-0 Wagener, M., & Walther, T. (2024). Teilhabepraktiken in jahrgangsgemischten Kindertandems. Erkenntnispotenziale von Videoanalysen für inklusiven Unterricht. In G. Wilm, R. Koßmann, S. Böse, M. Fabel-Lamla, & C. Meyer-Jain (Eds.), Videographische Forschung zu inklusivem Unterricht: Erziehungswissenschaftliche und fachdidaktische Perspektiven (pp. 48–64). Verlag Julius Klinkhardt. https://doi.org/10.35468/6098-04 Yin, R. K. (2018). Case Study Research and Applications: Design and Methods. SAGE Publications, Inc.