«The diversity of the minds is the great obstacle of all (school based) education» (Herbart). This quote illustrates most aptly one of the most important problems of modern schooling. In recent times standardization of teaching/education was identified as ultima ratio in education to solve the core problem of 'performance heterogeneity' as it was expressed by various students assessment studies (see TIMSS, PIRLS; PISA).

Consequently, there is a broad discourse on diversity in education. At the heart of it one will find the debate on the meaning of differences between students from an age group and their implications for school based learning. Even more basically didaktik has to give a response on the dilemma arising of balancing "individual" and "collective" modes of teaching. Mainly two concepts stand out: On the one side, one will find sharp criticism of previous strategies of homogenization and of ignoring. On the other side one will find arguments for acceptance of differences between students. Seen from a more theoretical point of view, it turns out that these concepts contain more programmatic aims than they do in reality.

Diversity arises as a mode of perception of difference (i.e. deviation from something interpreted as normal(ity)), which means that one finds itself in the state of not-knowing(-yet). Therefore, heterogeneity is directly linked to the experience of alienation. In this manner, it becomes clear that heterogeneity is nourished by the experience of the other, the stranger. The strangeness of the stranger works as a cognitive-cultural, social, linguistic or even geographic filter.

It is also true that modern teaching is facing heterogeneous students. Ironically, this is not a recent development: students have always been different. Basically, it is about the dilemma of simultaneousness: diversity – and so the stranger – is present in a simultaneous way and rising over time. Traditional didaktik theory speaks of generalized homogenized students, axis-constructions and vertexes in singular, denying their heterogeneity. So, how can the teacher’s relation to this simultaneous heterogeneity be carried out in justified way? One answer might be seen in the understanding of the strangeness of the other.

The aim of the symposium is therefore to analyze the constructions of diversity in education based on the leitmotif of the stranger. In so doing, the stranger is seen as a didactic key. In this respect, didactics must relate according to this. It shows that there is a necessity to understand the filter of strangeness/ otherness. One has to ask for criteria for establishing the filter; more precise: relevant mechanisms of this filter. This is done in the hope that the results are not only fruitfully for intercultural education but even so for didaktik. The symposium will not seek to produce more programmatic aims or rashly offer "recipes", but provide a theoretical analysis of the challenges arising from the other, the unknown – the stranger. Therefore, a theoretical as well as an empirical inquiry is essential to get at a realistic assessment of the framework for didaktik. The symposium is organized along the two branches: theorizing diversity & teaching in diversity.