This study concerns student teachers' views of the behavior of supervisors during the school practice periods in two Finnish Teachers' Colleges. It is divided into four parts. In part one, the structure of the behavior of supervisors as assessed by student teachers is analyzed, and the concepts used to describe the behavior are defined. Part two deals with the general problems of studying behavior, and a method for interpreting behavior by relationships between the concepts of a behavior is developed and discussed. In part three, the relationships between the concepts of the behavior of supervisors are defined by the method for interpreting behavior. Part four gives the interpretations of the behavior of supervisors based on the information about the relationships between the concepts of the behavior. The study gives primarily diagnostic knowledge about the behavior of supervisors and emphasizes the need to continue analyses to find out how the behavior should be changed to achieve better results in supervision. (JD)