In the time of a growing pressure of globalisation and internationalisation on national education systems262, it is difficult to define exactly what terms like international education or related ones like international schools mean. In this context, Murphy (2000: 6) pointed out: “No one has so far come up with a definition of ‘international school’ that does not exclude some schools which consider themselves international, and does include others which may not [...].” In her definition on schools that explicitly use the attribute “international” in their title, Hornberg (2010: 154) differed between the following types: - International schools in the form of schools abroad with elements of private schools, that are founded by a country in another country abroad and that award the curriculum as well as the degree of the founding country. - International schools in the form of private schools that offer the curriculum and the degree of the host state and that offer one or multiple foreign curricula or degrees. - International schools in the form of private schools that offer international or foreign curricula or degrees (e.g., international baccalaureate). - State schools that offer their students to follow international branches in addition to the national curricula and degrees. In the following, general development tendencies of the international school segment will be presented in more detail. On the one hand, these developments refer to the growth and increasing differentiation of international schools. On the other, they refer to their form of education. In the second part, special focus will be placed on the international state of research on international schools. Further, research deficits will be shown. Finally, there will be a reflection on theoretical contexts [e.g., the concept of “transnational social space” developed by Beck (2000)] and to research perspectives to this research field.

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