Research supervision can be investigated from social-emotional and cognitive perspectives, but most studies include only one perspective. This study aims to understand the interplay between a social-emotional (supervisor-student relationship) and cognitive (feedback) perspective on the outcomes of master's thesis supervision in specific, by investigating student perceptions of both perspectives. Questionnaire data (N = 1016) were collected and analysed using regression analyses. For student satisfaction (SS) and students' perceived supervisor contribution to learning (PSCL), affiliation by far is most important, followed by control for SS and feedback-forward for PSCL. Also, interaction effects between feedback and interpersonal perceptions were found, indicating that the role of feedback perceptions is most important in situations in which no optimal supervisor-student relationship could be established. Findings imply the importance for master's thesis supervisors of creating friendly and helping relationships with students and if this is problematic, extra care should be taken with giving feedback.