Considering today’s competition-based systems and developments on the international stage, one can appreciate the importance of raising individuals possessing the skills that respond to the requirements of our age (Miaoulis, 2009). For this reason, investment in science, technology, engineering, and mathematics (STEM) literacy are very much on the increase. In STEM education, as in all educational systems, this investment and support focus on the students, teachers, and training programmes and the efficiency and effectiveness of educational systems depend on these three elements moving in harmony towards a specific target. A breakdown, weakness, ineffectiveness, or malfunctioning in any of these elements is bound to lower the efficiency of the whole system. Today, academic performance and a positive change in students in terms of various skills are considered to be the barometers of efficiency and success in education.
The most important factor in ensuring these positive changes in students in terms of various skills and academic performance is, undoubtedly, the teacher (Rivkin, Hanushek, & Kain, 2005), because, as pointed out by researchers who have studied the link between the exercise of the profession and the learning outcomes, a crucial relationship exists between teachers’ adequacy and students’ performance (Hoy & Miskel, 2008; Junor-Clarke & Fourniller, 2012; Guskey, 2014). Training well-qualified teachers is only possible through an effective implementation of the pre-service and in-service educational activities (Darling-Hammond, 1999; Darling-Hammond & Bransford, 2005). In order for teachers to keep up with the contemporary requirements of the educational sector in their professional lives and to educate individuals possessing the skills demanded of them, they need to constantly refresh their capabilities and take part in the in-service training activities organized for this purpose. The link between in-service training programmes and teachers’ professional development directly affects school development and students’ learning quality (Kennedy, 1998). When this interaction is taken into account, the need for a proper assessment of the targets and structuring of these in-service training programmes cannot be missed.