This is a research based on a relational survey model that determins the effects of the theoretical and applied studies on skill of the principles and methods course on teacher candidates. The research was carried out according to two basic aims. The first aim is to determine the effects of the theoretically-oriented cognitive learning, which is acquired based on instructors' lecture, and the level of concrete experience provided by microteaching applications, which are adopted from Kolb's learning model, on the skills of lesson plan preparation and application. The other aim is to test the mediating effect of the skill of lesson plan preparation on the relationship between the application of lesson plan and cognitive learning with concrete experience. The research used the scores of 96 teachers who were sophomores at the department of Teaching Mathematics at Primary School at Kocaeli University. As a result of the research, while it was found that, in terms of regression value, lesson plan preparation was affected more by theoretical learning; and lesson plan applications were affected more by concrete experience, it was also found that lesson plan preparation skill is an important mediating variable.