The discussion of psychodiagnostics is conducted from a microsocological perspective; the diagnostic process is analysed as a form of interpersonal interaction. The author examines the structural features that characterise psychodiagnostic interaction between psychodiagnostic and client communication, decision-making on client empowerment and imbalance in psychodiagnostic interaction. The structural model of psychodiagnostic interaction outlined on this basis shows that these hierarchical relationships imply and cannot be linked to action-related episodes of emancipatory aims. Finally, the author suggests some examples of ‘subversive psychodiagnostics’, which come from the field of special needs education and focus on the development of teacher-centred psychodiagnostics and support for non-repressive behaviour. (KS)