Academic libraries have a long tradition of collecting, preserving, and offering access to information about doctoral dissertations through the repositories of electronic theses and dissertations. In recent years libraries have turned their attention to Wikidata as a knowledge graph for publishing structured data on the Web. These initiatives include the publication of metadata about theses and dissertations. However, Wikidata is a sociotechnical infrastructure, where the responsibility for its development is in the hands of its users. This includes asynchronous collaborative work on its ontology by many non-expert users. This may cause tensions between traditional metadata control and socially developed schemas. The goal of this article is to develop a conceptual understanding of the representation patterns of doctoral dissertations in a socially constructed Wikidata knowledge graph. This study uses an interpretative approach guided by the method of the close reading of the infrastructure to develop an understanding of what a doctoral dissertation is in this socially constructed representation of reality and how doctoral dissertations are described using Wikidata ontology. The ontological status of the doctoral dissertation is revealed by interpreting the place of this concept in the taxonomic structure of the Wikidata ontology. The expressiveness of Wikidata ontology for the description of doctoral dissertations is limited to three selected properties, authorship, doctoral advisor, and the institution to which the dissertation was submitted. The results of this study show on the one hand the redundancies in modelling doctoral dissertations, and on the other inconsistencies in the descriptions. This calls for close attention from libraries to metadata curatorial practices in Wikidata sociotechnical infrastructure.