Globalization and rapidly changing life circumstances are leading to a growing diversity of individuals’ backgrounds which is observable in many settings, such as in schools. This can be understood as a growing uncertainty, but also as a chance since it broaches the issue of dealing with diversity and exclusion of marginalised groups to public opinion as well as to politics, especially in the educational system (Booth & UNESCO, 2003). The changing student composition in schools is highly relevant to the educational system since all children, regardless of their individual requirements, have the right to receive education of high quality. Inclusive education is an ideology that not only aims at dealing with, but also at valuing diversity (Booth & Ainscow, 2002). It targets identifying and overcoming discrimination and barriers to inclusion, thus, enabling access to non-discriminatory education for all students attempting to teach skills and capacities that allow participation in democratic societies (UNESCO, 2005). Studies often report teachers to feel overburdened dealing with the heterogeneous needs of students which they face in their classrooms (Avramidis & Norwich, 2002). In order to support teachers developing inclusive teaching cultures and practices, professional development programs (PDPs) are necessary (Heimlich, Kahlert, Lelgemann & Fischer, 2016).

Since inclusive educational reforms are required in many countries, and often supported through PDPs for in-service teachers (Waitoller & Artilles, 2013), it is important to comprehend and estimate the influence of PDPs.Therefore, he present paper analyses whether inclusive PDPs have an effect on in-service teachers and which target variables are influenced by inclusive PDPs.

In order to answer this question, a systematic literature search was conducted to identify research work evaluating the effect of inclusive PDPs on in-service teachers. More than 40 papers were identified, working qualitatively and quantitatively, and were included in a meta-analytic as well as a review analysis. The reported PDPs showed a wide range of diversity concerning their structure, length, content, amount of activities and participants. To measure the effects of PDPs, the original studies were based on diverse indicators. The reported effects were grouped into six categories: 1.) attitude towards inclusion and concerns, 2.) teachers’ self-efficacy, 3.) changes in knowledge, 4.) implementation of inclusive strategies, 5.) perception of inclusive strategies and 6.) attitudes towards the program.

For the present paper, the results on the change in teachers' attitudes towards inclusion will be presented. Influences of the structure and methods of presentation of PDPs will be reported. This meta-analytic review represents an important basis for the development and design of future professional development programs that support in-service teachers in their movements towards inclusive education.

Avramidis, E., & Norwich, B. (2002). Teachers' attitudes towards integration / inclusion: a review of the literature. European Journal of Special Needs Education, 17(2), 129–147. Booth, T., & Ainscow, M. (2002). Index for inclusion: Developing learning and participation in schools. Bristol, United Kingdom: Centre for Studies on Inclusive Education (CSIE). Booth, T., & UNESCO. (2003). Overcoming exclusion through inclusive approaches in education: A challenge & a vision; conceptual paper. Paris, France: United Nations Educational, Scientific and Cultural Organization (UNESCO). Heimlich, U., Kahlert, J., Lelgemann, R., & Fischer, E. (Hrsg.) (2016). Inklusives Schulsystem: Analysen, Befunde, Empfehlungen zum bayerischen Weg. [Inclusive school system: Analysis, Results, Recommendations to the Bavarian Path.] Bad Heilbrunn: Klinkhardt. UNESCO. (2005). Guidelines for inclusion: Ensuring access to education for all. Paris, France: United Nations Educational, Scientific and Cultural Organization (UNESCO). Waitoller, F., & Artilles, A. (2013). A Decade of Professional Development Research for Inclusive Edication: A Critical Review and Notes for a Research Program. Review of Educational research, 83(3), 319-356.