This study is about what supervisors perceive as crucial aspects of quality in supervising students writing their bachelor theses. The questions on quality are related to a scientific perspective, a learning perspective, a societal perspective and a social perspective. The study demonstrates that the criteria on science varied considerably, despite the supervisors being in a single discipline area. There is also marked variation in views of the relation between science and practice and different supervisors expressed variations in their conception of competence. Furthermore, supervisors perceive their own role as senior researchers or senior consultants, and sometimes also in the supporting role of "deputy mother." The conclusion is that the supervisors seem to have a marked lack of understanding of the differences between them in undertaking their role. A main reason for this seems to be the lack of a common theoretical frame of reference. Due to a lack of communication, possible problems related to different perceptions of understanding the task may remain hidden or at least be neglected and underestimated.