Abstract. Active learning instruction is promoted by the most recent version of the National Program for the Development of Education in Kazakhstan as it is believed to provide more meaningful learning and deeper understanding compared to traditional instruction. In order to achieve greater utilization of the instructional approach at schools, teachers must be aware of active learning techniques and know how to use them. This paper studies whether 'apprenticeship of observation' during a graduate course using active learning techniques has an impact on novice and experienced teachers' attitudes towards active learning instruction. The study used data from a survey of students taking the course, which was focused on educational issues rather than methodological training. The results of the study confirmed the hypotheses that 'apprenticeship of observation' has an influence on teachers not only during pre-service training, but also at later stages of their careers, when they become involved in professional development or continuing education. This influence was especially obvious for teachers with no or little exposure to professional development. Based on these results the paper also suggests some practical implications. Limitations and biases that could affect results are also mentioned. Keywords: active learning instruction, apprenticeship of observation, professional development of teachers, in-service training of teachers.