Modern life is dominated by changes in all aspects of life. That is why it is necessary to reshape education from traditional to modern in which the student is an active participant, a creator of their own knowledge, and adaptable to changes. This implies both active learning and the educators’ competence in this form of teaching. The aim of this doctoral thesis is to examine the application of active learning strategies to teaching methods in primary-level Nature and Society education in the Republic of Croatia. A further aim is to examine the self-assessment of both students (future primary education teachers), and teachers, with a particular focus on the implementation of active learning teaching strategies to Nature and Society classes (an interdisciplinary subject). The research was conducted on a sample of 290 primary education teachers in 290 in Croatian primary schools and 227 4th and 5th year Teacher Education students, also in Croatia. For the purposes of the research, a questionnaire was designed for students and teachers. The first part of the questionnaire consisted of sociodemographic teacher characteristics (years of work experience, school, county, class, professional training) and students (Faculty and years of study). The second part of the questionnaire consisted of three sections that were the same for teachers and students: 1. A questionnaire for examining the frequency of active learning teaching strategies application in Nature and Society, which is divided into 5 thematic subscales named according to the active learning strategies including descriptions of learning activities (collaborative learning, communication skills and learning skills, problem-based learning, setting goals and giving feedback, and active learning with the use of information and communication technology) (Haas, 2002) 2. A self-assessment questionnaire with a focus on competences for effective organisation and execution of Nature and Society lessons (Letina, 2013) 3. A questionnaire about the advantages and obstacles in the implementation of active learning strategies in the teaching of Nature and Society (Borić, Škugor and Perković, 2010). The results of all five thematic subscales show that teachers apply collaborative learning occasionally (once a month); communication skills, learning skills and problem-based learning often (once a week); that they set goals and give feedback almost very frequently (twice a week); while the least frequently used active learning strategy in Nature and Society is the use of communication and information technology. A negative and low connection between training in the implementation of active learning teaching strategies and the application of these same strategies in Nature and Society became apparent. The correlation coefficient is significant, too. An important result is that 77.9 % of the teachers who participated in this research received professional training in the implementation of active learning teaching strategies in the last five years. It also became clearthat there is no significant difference in the application of active learning strategies between teachers who teach in the first and second grades and those who teach in the third and fourth grades. The assumption is that district school teachers (in rural areas) implement more active learning strategies, such as exploratory extracurricular classes, than teachers in home schools (urban areas). Although this was not an explicit research goal, I became apparent that there was no statistically significant difference between the two groups of respondents. The results show that active learning teaching in Nature and Society are most often applied by teachers who have between 6 and 10 years of work experience and by teachers who have more than 25 years of work experience. Students estimate that they will apply collaborative learning, communication and learning skills, problem-based learning, and goal setting and feedback frequently, while occasionally also using communication and information technologies. Through a comparison of the teacher and student responses, it became clear that both groups prioritise the strategy of setting goals and giving feedback. For teachers, communication skills and learning skills are of secondary importance. Problem-based learning is of tertiary importance. The reverse is true for students. Students' preference for problem-based learning over communication and study skills can be explained by a lack of practical teaching experience. Both teachers and students put cooperative learning in fourth place. The use of information and communication technology is gauged as the least important. This is an expected finding given than 46.5 % of teacher respondents have more than 25 years experience. However, this stance is unusual for students who are digital natives. Furthermore, the findings showed that both teachers and students estimate that they are most competent in connecting lessons with seasonal environmental changes and connecting the teaching content of nature and Society with other subjects. They feel the least competent in theoretical knowledge. It is noteworthy that they perceive themselves as more competent in the organisation and preparation of active learning teaching strategies in Nature and Society, than it the application. Teachers assess their competences as the least developed in the field of knowledge of constructivist concepts of learning and in the knowledge and application of various strategies and methods of active learning. Students assess their competencies as the least developed in the knowledge of the project process and project product, in knowledge of constructivist concepts of learning, and in the ability to work in an interdisciplinary team of teachers to organise extracurricular Nature and Society classes. Both teachers and students self-assess their active learning strategies application in Nature and Society, as developed. Teachers further assess their competences for applying active learning as more developed than students. The findings confirm that there is a statistically significant difference in the self-assessment of the adoption and application of active learning teaching strategies in Nature and Society between teachers and students. Likewise, the findings suggest that there is a strong positive connection between more developed teacher competencies and more frequent application of strategies. In the final analysis, the findings show that there is a significant difference in the evaluation of competencies for implementing active learning strategies between students in the final year of Teacher Education and students in the lower years of Teacher Education. The findings also show that teachers perceive the advantages of applying active learning strategies in Nature and Society while students mostly agree that there are advantages in applying these strategies. The findings also show that there is no significant difference in the perception of the advantages of active learning strategies between teachers and students. Further, there are no statistically significant differences in the assessment of the advantages and obstacles of active learning teaching strategies between teachers more and less experienced teachers. The difference in assessment among students was also examined. The findings indicate that there are no statistically significant differences in the assessment of advantages and obstacles to active learning teaching strategies between students in the 4th and 5th year of study. Competencies are a significant positive predictor of application as well as assessment of advantages and obstacles; the higher the self-assessment of personal professional competences for the implementation of active learning strategies, the more frequent their application in the teaching of Nature and Society and the higher the assessment of advantages in relation to obstacles. A detailed presentation of the relevant theoretical and empirical research, in both the national and international contexts, is the cognitive driver of this research. The scientific and applied contribution is located in the empirical part of the thesis, which provides insights into the frequency of active learning teaching strategies’ application in Croatia; into the self-assessment of the competencies of 4th and 5th Teacher Education students and primary education teachers; into the application of active learning teaching strategies in the teaching of Nature and Society. It also evaluates advantages and obstacles in the implementation of active learning strategies findings. The contribution of this doctoral work lies in the opening of new questions and avenues for future research that could contribute to the more frequent application of active learning strategies in school practice, and thus also to raising the quality of education. For example, determine why the strategy of using information and communication technology and the strategy of collaborative learning are less frequently applied in classroom teaching as well as determining the causes of young teachers' lack of interest in training at the beginning of teaching, examining teachers' opinions on whether there is a need for a more modern curriculum for Nature and Society, and examining the need for more frequent practical participation in classes. This research also contributes to the continuous involvement of students in real-life teaching processes across their entire education, as well as to the reduction of Nature and Society’s curriculum outcomes, which benefits teachers both in terms of planning time and the organisation and implementation of active learning methods. A desirable consequence of this would be a more frequent application of active learning strategies in classes encouraging students to engage in independent activities, enabling them to acquire new knowledge based on direct experience, and training them for lifelong learning and successful adaption to the challenges of future societies.