This research documented an attempt to introduce a change in teachers' working methods in several Israeli schools through the use of in-service teacher training courses (INSET). The courses were held in the Oranim School of Education of the Kibbutz Movement. Oranim is a comprehensive teacher training college, offering a wide variety of training courses for educators and school teachers at all levels. This research study focused on two main objectives: 1. To investigate the suspicion that Oranim course graduates are not implementing the material learned in the course in their classes. This was noticed by the researcher and her colleagues during their visits to numerous schools. This objective was to more systematically investigate if this feeling reflects reality. 2. To investigate how teachers and head-teachers explain this phenomenon, that is, their ability (or inability) to implement new methods, techniques and didactic means learned in the course in their classes. The first objective was examined both by reviewing the reality through observations, questionnaires and interviews, as well as by making comparisons to work methods and opinions of teachers who did not participate in the course. The second objective was examined through interviews and questionnaires. The main research fmdings showed that the course participants differed from their colleagues who did not participate in the course with respect to their level of awareness of the need to implement change, and their familiarisation with diverse teaching-learning methods. The two groups of teachers actually worked in a similar fashion. The main explanations provided by the teachers for this were: lack of follow-up by an expert after the course; lack of cooperation by the school's teaching staff; and insufficient preparation in order to cope with their unique reality during the course.