The aim of this study is to analyze changes in beliefs and attitudes to the teaching profession and to classroom management as a result of teaching experience. The structure of this study is based partly on the COACTIV-model of professional competence of teachers. The COACTIV-model is divided into motivational orientations, convictions and basic attitudes, self-regulatory skills and professional knowledge (comprising general pedagogical knowledge, content knowledge, pedagogical content knowledge, organisational knowledge and consulting knowledge). There are many studies that investigate the development of professional knowledge from novice to expert teachers. However, there are very few studies that analyze the impact of teaching practice on the convictions and attitudes of teacher trainees. Blömeke et al. analyzed the epistemological beliefs (beliefs regarding the structure of mathematics and those regarding the "?genesis of mathematical competence"?) of mathematics teacher trainees at the end of their training period. Brunner et al. have demonstrated that teacher's beliefs have an impact on the teaching practice, Sosu and Gray observed a positive relation between constructivist conviction and the learning process. Teachers who are convinced of the constructivist approach allow more self-directed and student-centered learning within their lessons. These teachers reject transmission conviction, suggesting that they should also reject teacher-centered lessons. Krauss et al. demonstrate that teachers with a good pedagogical content knowledge and a good content knowledge prefer a constructivist approach. It is the subject of this research to analyze whether teacher trainees, who favor a constructivist approach change their convictions as a result of the practical experience leading to a possibly more teacher-centered lesson style.