Repo4Cat and Voc4Cat: Integration of External Vocabularies into Dataverse Repository. Experience Report NFDI4Cat and TS4NFDI.

Catalysis research has been historically hindered by a lack of digitalization of research data, which has made it difficult to effectively share information and results among researchers in the field, slowing down the pace of progress and limiting the effectiveness of further development in the area. To address this issue and to organize an efficient and FAIR [1] storage and management of the user data and metadata, the NDFI4Cat project [2] has provided a comprehensive research data infrastructure including a central data repository "Repo4Cat" [3] as a key component to store, share and publish the data. Repo4Cat repository was built based on the Dataverse repository software [4] and was adapted to specific needs of the catalysis research community. A crucial role here played a customization of the metadata. Due to the lack of catalysis-specific vocabularies and ontologies, NFDI4Cat has created a community-managed SKOS vocabulary "Voc4Cat" [5] to provide machine readable term definitions to be used for data annotation and in metadata schemas. The Dataverse functionality allows to use external vocabularies within metadata schemas, but for that some additional programming effort is usually needed. Cooperating together with the Base4NFDI basic service Terminology Services 4 NFDI (TS4NFDI) [6] NFDI4Cat was able to customize Repo4Cat providing a better vocabulary browsing and search experience by serving Voc4Cat via Skosmos, a terminology repository which is specialized to browse SKOS vocabularies. It was also possible to experiment with the integration of Voc4Cat annotation-widgets in the Repo4Cat data repository in order to improve the metadata entry and interoperability. In this work we want to share our experience in the metadata customization of Repo4Cat, as an example of a Dataverse repository, using an external SKOS vocabulary on the example of Voc4Cat. The following contribution aims to demonstrate the integration and automated updating of Voc4Cat within the Skosmos-based terminology service. Furthermore, the necessary adaptations of the Dataverse repository and additional scripts required for the integration of Voc4Cat data via the Skosmos-based terminology service will be demonstrated. The findings of this contribution could also assist comparable projects in the customization of their repository metadata.