A Human- and Machine-Readable Thesaurus for the Conservation of Archaeological Heritage - Development, Technical Implementation and Application in digital space

An important aspect for conservators and researchers is access to the latest research on examination methods, damage phenomena, conservation techniques and materials, as well as preventive measures. Professional exchange strengthens expertise in assessing object conditions and determining appropriate interventions. With the advancement of digitalisation, conservation is presented with increasing opportunities while simultaneously encountering the challenge of ensuring the digital accessibility and reusability of complex expertise and valuable data [1], [2]. Not only is conservation-related data scattered across isolated databases and stored in different formats but the information is also described using different terminologies. Experts from various specialisations use distinct terms for similar concepts, leading to inconsistencies that complicate data retrieval, comparison, and integration [3], [4]. This lack of standardisation significantly hampers interdisciplinary collaboration, knowledge sharing, and the development of interoperable digital resources. To address these challenges, the "Conservation and Restoration Thesaurus for Archaeological Cultural Heritage" was developed at the Leibniz-Zentrum für Archäologie (LEIZA) as part of NFDI4Objects [5]. This controlled vocabulary not only facilitates human communication by standardising terminology but also enables machine-readable, semantically structured data integration for the Semantic Web [4]. Based on the Simple Knowledge Organization System [6], it ensures interoperability and follows the FAIR principles (Findable, Accessible, Interoperable, Reusable) [7]. To further support research-specific needs, such as the citation of sources, the schema was extended with additional properties. In addition the thesaurus aims to align with ISO and DIN standards in its content classification [8], [9]. To support the creation of the complex vocabulary a simple web application was developed. This web application validates tabular vocabulary data against the SKOS-based schema, detecting errors like duplicate identifiers or incorrect hierarchies. It provides different visualisations to represent hierarchical structures and allows collaborative content development through an interactive comment function. The validated data can be exported as an RDF turtle file and integrated into central thesaurus repositories like DANTE [10] and SkoHub [11] or LOD-Clouds like Wikidata [12]. The collaboration between domain experts and software engineers ensured both user-friendliness for professionals and machine readability for digital applications. Beyond structured vocabulary development, the enrichment of the thesaurus content as well was supported by technical innovations, like Natural Language Processing (NLP). One key approach was the analysis of digital and retro-digitised conservation reports from approximately 170 years of conservation history at LEIZA (formerly the Römisch-Germanisches Zentralmuseum). Conservation-specific terminology was extracted from these textual resources, classified, and integrated based on hierarchical, equivalent, and associative relationships. At the Conference on Research Data Infrastructure 2025, the methodological and technical aspects of thesaurus development will be presented as a poster. At the same time, the practical benefits of subject-specific thesauri should be clearly outlined, thus emphasising the importance of standardised vocabularies for research data management. It is anticipated that the 1.0 version of the Conservation Thesaurus will be made available to the public prior to the commencement of the conference, demonstrating how semantic technologies can enhance research in the field of digital humanities by overcoming long-standing communication and data integration barriers.