Quasi-identifiers or indirect identifiers are information or characteristics with which, in combination or by allusion to external information, a person can be indirectly identified. For higher education research and science studies, these are in particular the university, the subject of study or the nationality. For example, if an interviewee has indicated the Technische Universität Ilmenau, the subject of study materials engineering and a Portuguese nationality, and this information would be published, de-anonymisation would be possible. It should be noted, however, that the identification of a person is already complicated by the sample selection, as there is uncertainty as to whether this combination of characteristics is unique in the population. Nevertheless, such quasi-identifiers are either aggregated or deleted. Aggregation refers to the grouping of response categories or the grouping of metric characteristics. We coordinate the entire anonymisation procedure with the data protection officer of the DZHW and also take the research interests of our data users into account.