Construct systems and style preferences of 30 student teachers were investigated before and after student teaching using Gregorc's (1982) "Style Delineator" and Kelly's (1955) "Repgrid". The majority of student teachers were found to prefer styles of Concrete Sequential and Abstract Random. Constructs were elicited from students as they compared and contrasted different teacher role types (e.g., Best Teacher, Most Understanding). The "Planet" computer program (Shaw, 1982) was utilized to determine similar patterns and relationships that existed in the subjects' construct systems. As predicted, students whose style preference was Concrete Sequential had a tendency to rate all the teachers with negative or positive characteristics the same on the repertory grid. An analysis of the constructs revealed categories of: personal traits, teaching qualities, and techniques. Shifts in styles were found to have corresponding changes in underlying cognitive structures. Awareness of style types and cognitive structures appears to need further research and consideration for inclusion in teacher education practices. (Author)