Generally speaking, metadata schemas serve the systematic description of objects or content as well as the relations between them. The definition of entities and their specific properties is essential here, although, strictly speaking, the boundary between description and definition becomes blurry.

In principle, metadata schemas can be defined for any area, but they only yield maximum utility when they are established as a widely accepted standard. The added value consists mainly in the fact that data sets that are compatible in terms of content can be clearly related or linked to each other (Interoperability). In this respect, metadata schemas also play an important role with regard to the fulfilment of the FAIR-Principles. The mapping of a metadata schema can take different forms, such as lists, tables or XML. A graphical representation can be given as a so-called Entity-Relationship-Diagram (ERD). The associated concept of the entity-relationship model (ERM) seems to be identical in meaning to "metadata schema".

From the perspective of VerbaAlpina, metadata schemas primarily play a role with regard to the management of our own data stock. Here, a project-specific, non-standardised, but nevertheless documented metadata schema is applied. Established standard metadata schemas are mainly used to export VA data to external data repositories. In the course of being transferred to the Open Data Repository of the LMU University Library, the core data stock of VerbaAlpina, i.e. the georeferenced and concept-related morpho-lexical material from VA_DB, is described with the metadata schema Datacite curated by the consortium of the same name. In addition, the core data holdings of VerbaAlpina are mapped in the metadata schema CIDOC-CRM, which aims to provide in-depth content indexing of the material. CIDOC-CRM is usually referred to as an "ontology". The mapping of the VA data to the classes and properties defined there and the subsequent formal representation of the result, which then combines the primary VA data and the secondary CIDOC-CRM metadata synoptically, nevertheless justifies calling CIDOC-CRM a "metadata schema". The example shows how fluid the transitions can be and how blurred the term "metadata schema" can sometimes appear. Irrespective of all terminological questions, the focus when indexing research data should essentially be on making metadata available in a structured form that follows an ontology in a common exchange format (e.g. RDF).

The indexing of the VA core data with both DataCite and CIDOC-CRM takes place within the framework of the research project eHumanities – interdisziplinär, which has been funded for three years (until 2021) by the Bavarian Ministry of Science and the Arts and addresses the challenge of research data management (FDM). VerbaAlpina has the status of a pilot project within eHumanities – interdisziplinär.