Since the ancient times, countries all over the world have been making an effort to reform their education systems with the purpose of keeping up with the times. In today’s world that is, in the age of information, technology and innovation, catching up the developments and maintaining economic competitiveness can be realized with raising individuals who are competent in different disciplines. STEM Education (based on the integration of the science, technology, engineering and mathematics disciplines) includes not only conceptual, procedural and attitudinal contents of disciplines involved in STEM but also the connections that exist between them (Martín‐Páez et al., 2019). Therefore, STEM education has been receiving much attention in many countries in recent times (DeCoito and Myszkal, 2018). STEM education can prepare students by developing their 21st century skills required for the information, technology and innovation age. In other words, STEM literate individuals can be raised with STEM Education. STEM literacy refers to “the capacity to identify and apply content from STEM knowledge areas to understand and resolve those problematic situations that cannot be concluded from a mono‐disciplinary approach” (Martín‐Páez et al., 2019, p. 2). For the development of STEM literacy, it is necessary to raise teachers who are equipped with a set of core knowledge and skills for each of the disciplines involved in STEM and have high level self-efficacy for teaching STEM Practices. Gardner, Glassmeyer and Worthy (2019) stated that educators should be supported to improve their STEM content knowledge, change their teaching practices and especially build their self-efficacy about subject-matter integration for effective STEM Education because content knowledge and quality pedagogy consist of a large part in self-efficacy (Stohlmann, Moore, & Roehrig, 2012). According to Bandura (1995), self-efficacy is “the belief in one’s capabilities to organize and execute the courses of action required to manage prospective situations” (p. 2). Appleton and Kindt (2002) mentioned that teachers generally prefer teaching strategies according to their self-efficacy and beliefs about teaching and learning. In addition, Davis et al. (2006) emphasized that teachers’ behavior, performance and practice are affected from their self-efficacy. According to Enochs and Riggs (1990),teachers can change their teaching strategies and practices when their beliefs change. Therefore, teachers’ self-efficacy is extremely important for successful teaching (Stohlmann, Moore & Roehrig, 2012). If science teachers’ self-efficacy for teaching STEM practices is high level, teachers can choose STEM as teaching strategy and the quality of their STEM practice can be better in science classrooms. In this way, teachers can raise individuals, capabling of solving real life problems by using different 21^st century skills. Teacher education programs are important to raise future science teachers having high self-efficacy for STEM practices. The present research was designed for determining the effectiveness of STEM Education on pre-service science teachers' (PSTs’) self-efficacy for teaching STEM practices since PSTs are future STEM implementers and their self-efficacy level is crucial in terms of using STEM in their classes and developing their students’ STEM literacy. Therefore, the research question of current study is;

‘Is there any statistically significant effect of STEM education on pre-service science teachers’ (PSTs’) self-efficacy for STEM practices?’  

This research was conducted with a one-group pre- and post-test research model. In this model, a one group is measured or observed before and after exposure to some sort of process (Fraenkel, Wallen & Hyun, 2012). The current research was carried out with 20 female PSTs during "STEM education" course at public university in Istanbul,Turkey. The practice period of the study took total of 5 weeks. At the beginning of course, “Teacher Self-Efficacy Scale for STEM Practices”, developed by Yaman, Özdemir and Akar Vural (2018), was applied to PSTs as a pre-test to determine their self-efficacy for teaching STEM Practices. In the scope of the course, general information about definition of STEM education, its history and importance were given by the instructor in the 1st week. Then, during 4 weeks, PSTs made different STEM practices collaboratively in groups consisting of 5 students and followed the steps of engineering design process by taking notes about what they do in every steps. Engineering design process includes 9 steps which are: 1. identifying need or problem, 2. research need or problem, 3. developing possible solutions, 4. selecting best possible solution, 5. constructing a prototype, 6. testing and evaluating solution, 7. communicating the solution, 8. redesigning and 9. completing decision (Hynes et al. 2011). The practice process was conducted in the context of "Mechanical and Static" subject. In the 2nd week, PSTs constructed space vehicle which able to descend on Mars planet without being damaged by using different materials pipette, plastic bag, string, band and paper. In the 3rd week, PSTs constructed ‘Spacecraft Milo’, capabling of moving on inclined surface of planets’ land without falling from surface, having a sensor to perceive foreign objects in front of it, and exploring on planets. In the 4th week, PSTs constructed the prototypes of earthquake resistant building by testing the effect of balanced and unbalanced forces on buildings’ movements. In the 5th week, teacher candidates made STEM practice by designing a swing bridge prototype. During all STEM practices, students thought on how they can design and discussed logical reasoning of different prototypes that they constructed with their group mates. After 5 weeks, “Teacher Self-Efficacy Scale for STEM Practices” was applied to PSTs as a post-test. In data analysis, in order to compare PSTs’ self-efficacy pre- and post-test scores, a paired-samples t-test was used since the difference scores of pre- and post-test scores showed normal distribution.

The effects of STEM education on PSTs’ self-efficacy for STEM practices were examined in this research. Results showed that there was a statistically significant difference between PSTs’ self-efficacy pre- and post-test scores in favor of PSTs’ post total test scores (t (19) = -5.348, p<.05). In other words, findings revealed that STEM education is effective way of developing PSTs’ self-efficacy for STEM practices. Effective STEM education is crucial for preparing individuals for life in the information, technology and innovation age. Teachers have an important role at this point. Implementing STEM can be complex process for teachers. Teachers’ self-efficacy about implementing STEM effectively is one of the essential part of successful STEM education. According to Honey et al. (2014), “teachers' content knowledge in the subjects is one of the limiting factors to teacher effectiveness and self-efficacy” (p. 7). For this reason, the preparation and support of PSTs, future science teachers, is an important necessity for STEM implementations. In other words, ensuring PSTs’ having high self-efficacy in teacher education programs is a crucial issue for applying STEM practices effectively in future learning environments.Therefore, in this research, it was benefited from STEM practices in order that PSTs could develop their content knowledge about STEM and self-efficacy for STEM practices. Although STEM Education has been part of education systems across the world for a while, there is a limited research that examines PSTs’ knowledge, beliefs, skills, experiences and especially self-efficacy required for effective implementation of STEM education. In this respect, this research can contribute to the current literature in terms of presenting a way about how PSTs’ self-efficacy for STEM practices can be developed with STEM Education. In the light of this research, future research can focus this issue more and present new approaches to improve PSTs’ self-efficacy for implementing STEM.

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