Greece was among the countries which agreed to follow the principles of the Salamanca Statement (UNESCO, 1994) for the education of students with disabilities within the mainstream education system. As a result, new legislation promoted the development of new pedagogical practices that promote inclusion (Law 2817/2000). Among these practices co-teaching was introduced for the enhancement of the education of students with disabilities in mainstream classes. According to Mastropieri and Scruggs (2006), co-teaching usually consists of a mainstream and a special education teacher in a mainstream classroom where students with and without disabilities learn together.

Although co-teachers have indicated several positive outcomes for themselves and their students with disabilities in several countries (Saloviita & Takala 2010; Strogilos, Tragoulia & Kaila, in press; Scruggs, Mastropieri, & McDuffie, 2007; Thousand, Villa, & Nevin, 2006), research on the efficacy of co-teaching remains limited (Cook, McDuffie-Landrum, Oshita, & Cotheren-Cook, 2011; Murawski & Swanson, 2001) with varying student outcomes (McDuffie, Mastropieri, & Scruggs, 2009; Moin, Magiera, & Zigmond, 2009; Murawski & Swanson, 2001). However, research results on the efficacy of co-teaching is still considered sparse and inconclusive (Cook et al., 2011), since few studies have indicated a medium to strong positive relationship between student outcomes and co-teaching (McDuffie, et al., 2009; Murawski & Swanson, 2001), while others have failed to identify benefits for students with disabilities in co-taught classrooms (Boudah, Schumacher, & Deshler, 1997; Murawski, 2006).

Internationally, the empirical research on co-teaching has focused on the impact of instructional activities and procedures (Magiera & Zigmond, 2005; McDuffie, et al., 2009; Moin, et al., 2009) and the responsibilities of co-teachers (Dieker, 2001; Weiss & LIoyd, 2002) in order to evaluate its efficacy on the education of students with disabilities. Specific activities and responsibilities of co-teachers, such as the active involvement of both teachers in the co-teaching of students with disabilities, the modification of the curriculum and the participation of students with disabilities in the whole class and small group work have been identified by the literature as essential prerequisites for the effective inclusion of students with disabilities in co-taught classes (e.g. Mc Duffie, et al., 2009; Moin, et al., 2009; Scruggs et al., 2007; Weiss & LIoyd, 2002). Yet, these factors are considered influential in improving students’ with disabilities behaviour and in enhancing their learning progress and social participation in the co-taught class. Thus, examining issues related to the above activities and responsibilities were deemed comprehensive for the development of this study, which aims at measuring the attitudes of co-teachers towards the efficacy of co-teaching.

More specifically, in this research we examine the influence of specific activities and responsibilities (i.e. the modifications of the curriculum, the integration of students with disabilities in mixed ability groups and the active involvement of mainstream education teachers (METs) in co-teaching students with disabilities) on the attitudes of co-teachers towards the social participation, behaviour improvement and learning progress of students with disabilities in the co-taught class. Within this framework, our research questions are:

1. Do teachers perceive co-teaching as an effective instructional strategy for students with disabilities’ social participation, behaviour improvement and learning progress?
2. Does the modification of the curriculum have a positive impact on teachers' attitudes towards the efficacy of co-teaching for students with disabilities?
3. Does the participation of students with disabilities in mixed ability groups have a positive impact on teachers' attitudes towards the efficacy of co-teaching for students with disabilities?
4. Does the active involvement of METs in co-teaching students with disabilities have a positive impact on teachers' attitudes towards the efficacy of co-teaching?

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