The obligation to implement inclusion, i.e., the joint learning of students with and without special educational needs, is one of the major challenges facing the German education system. But how does inclusion affect everyday school life, learning success, and social participation? Do inclusive learning environments only help children and young people with special educational needs, or do all students benefit equally? The nationwide research project INSIDE (“Inclusion in and after lower secondary education in Germany”) provides comprehensive longitudinal data on this topic for the first time, based on a five-year longitudinal study at 246 schools. Selected findings on the state of inclusion in schools are now being published in an anthology by the Journal of Educational Science (ZfE).
The interdisciplinary INSIDE project, a collaboration between the Leibniz Institute for Educational Trajectories (LIfBi), the Institute for Quality Development in Education (IQB), Humboldt University of Berlin (HU), the University of Wuppertal (BUW), and the University of Potsdam (UP), began in 2019 with more than 4,000 students with and without special educational needs (SEN) at 246 general education schools and accompanied them from the sixth grade through secondary school with surveys and competency tests. Their school administrators, teachers, specialists, and parents were also surveyed.
“We wanted to know how inclusion is implemented in schools in practice, what conditions promote inclusion, how students are supported, and what consequences joint learning has, for example, on their academic performance, their social interaction, and their further educational path,” says Dr. Amelie Labsch, head of the INSIDE project at LIfBi, summarizing the research goals of the project.
Inclusion in secondary education: A mixed picture
The INSIDE data is the most comprehensive longitudinal data set available to date for studying school inclusion in lower secondary education in Germany. The contributions to the ZfE anthology show that, in selected areas, inclusion in lower secondary education is neither consistently successful nor fundamentally unsuccessful. The research staff of the INSIDE project and other researchers in the field of education examine various inclusive framework conditions, such as the design of inclusive teaching by teachers and the development of inclusive learners. Among other things, the following topics are addressed:
- Teacher cooperation as a key factor
Cooperation between general education and special education teachers is central to successful inclusive teaching. Good preparation, high self-efficacy expectations, and a positive working atmosphere promote what is known as co-constructive cooperation. General education teachers tend to rate cooperation more positively than their special education colleagues.
- The use of digital media depends on the teacher
The use of digital media can be helpful in responding to the different learning needs and requirements of students. The INSIDE data show that teachers' inclusion-related self-efficacy is crucial to their attitude toward using digital media in the classroom to differentiate learning opportunities. Teachers who feel well prepared to teach inclusively are also more open to digital media in subject teaching and are more likely to see such media as an opportunity to support students individually.
- Inclusion and democracy education are positively correlated
There is a positive correlation between the inclusive design of a school (e.g., in terms of lesson planning or team structures within the school) and the perception of democracy education in the school. Students and teachers report a stronger democratic orientation in schools that actively strive to create inclusive learning environments.
- Competence development in inclusive education varies
The INSIDE study repeatedly examined the reading and math skills of all students. The results show that at the beginning of secondary school, i.e., from grade 6 to grade 7, all students improve their reading and math skills. However, as expected, learners with SEN demonstrate lower skills than learners without SEN, with the skills of students with a special educational need in learning being lower than those of learners with other special educational needs, such as language.
- Parent networks promote academic success
Parents play a crucial role in their children's educational success. This also includes the contacts that parents have with the parents of their children's classmates. The INSIDE data shows that such parental contacts within a class have a positive effect on the academic success of students with SEN if there are only a few children with SEN in a class.
- More differentiation – less learning success?
Universal Design for Learning (UDL) refers to principles that aim to make teaching accessible to all students – for example, through differentiation. Evaluations from the INSIDE study document that UDL principles are used slightly more frequently in German lessons than in mathematics lessons. In mathematics, there is a negative correlation between the application of UDL principles and student learning gains. The extent to which this surprising finding is related to class composition or general skill development in classes with low-performing learners is discussed in the article.
- Development of social skills in learners without SEN regardless of the inclusive learning context
The social skills of students without SEN do not develop systematically better or worse depending on whether they learn in inclusive conditions during lower secondary school or not. The class climate is decisive: appreciative relationships between teachers and students promote the development of social skills in children without SEN.
- Students with SPF feel less part of the class than their classmates without SPF
As expected, students with SPF report lower social participation than their classmates without SPF. This is particularly true for those with a focus on “emotional and social development.” During secondary school, all students' assessment of their social participation declines. An appreciative relationship with teachers can somewhat cushion this negative development.
- Individualized instruction can promote social participation among students
Individualized teaching practices in German and mathematics are positively correlated with students' social participation. The more students perceive that their subject teachers differentiate their teaching and thus adapt it to their individual needs, the more learners experience social participation. This is particularly true for those with SPF.
The anthology has been published by Springer in the ZfE Edition book series and can be read and purchased here:
To the complete anthology
Outlook: Data access for researchers
The findings from the INSIDE project published in the anthology give an impression of the wide range of issues that can be addressed using the INSIDE data. In order to generate further evidence-based knowledge about the challenges and successes of school inclusion, the research community's data package will be made available free of charge at the end of 2025 via the LIfBi Research Data Center (FDZ) and can be used for a wide range of questions and analyses.
Funding information
The INSIDE project “Inclusion in and after lower secondary education in Germany” is funded by the Federal Ministry for Education, Family, Seniors, Women and Youth (BMBFSFJ), formerly the Federal Ministry of Education and Research (BMBF).
About the INSIDE project