Hic sunt dracones: How to make modern data dragons LOUD and FAIR
Creators: name: Thiery, Florian
name: Mees, Allard W.
Publisher: name: Zenodo
Year: 2021
Subjects: Linked Data
Wikidata

description: Today, many archaeological data is usually stored in relational databases. One of the advantages of these storage technologies is e.g. referential integrity, allowing for well structured datasets. However, in order to reach web based interoperability and FAIR data, additional technologies such as machine readable interfaces and Linked Open Usable Data (LOUD) are compulsory. We call such data without a LOUD publication “modern data dragons”. Whereas SQL technology may cover just as well the F, A and R capabilities of the FAIR principles on local systems, web based interoperability (I) and Open Access (A) is clearly the advantage of the RDF-LOD technology. Enhancing SQL databases by applying LOD technologies enables the application of the RDF standard (I), semantic modelling (R), interlinking of data, and Open Access by offering a SPARQL endpoint.To support the development and publication of LOUD resources, the CAA Special Interest Group (SIG) on Semantics and LOUD in Archaeology (SIG-DataDragon) was established in 2020. Archaeological data is often characterised by hidden assumptions as well as vague and uncertain statements, which have to be made visible by using e.g. semantic modelling. The transformation process from relational structures into LOD has to be simple and applicable to other databases and modelling structures. As a consequence, the resulting data should be published as well as being made findable and accessible in catalogues of archaeological resources. This paper demonstrates methods and workflows to achieve LOUD and FAIR data with the example of the Samian Research database and the re3dragon – REsearch REsource REgistry for DataDragons – catalogue and API. In this study we are using the online database Samian Research, which is based on the Names on Terra Sigillata project, driven by Leeds and Reading Universities funded by the AHRC, the Corpus Vasorum Arretinorum and the RGZM at Mainz (RGZM 2021). The database comprises a quarter of a million potters’ stamps on Terra Sigillata, recorded from dated and non-dated sites from all over the Roman Empire. Since the same potter may have worked in different kiln sites, there is a vagueness in the possible attribution of potters to kiln sites. Vagueness and uncertainties also occur in the context of the determination of partial vessel fragments (e. g. when only a base fragment of a vessel is preserved) which may be attributable to different possible types of pot forms. The Samian database is structured in a relational database and accessible by online query masks, which were developed from the late 1990s onwards. The scientific data are ongoing curated by an active international research community. Although the series of interfaces comprise a RESTful API and WFS, Research Software Engineers (RSEs) would expect also LOUD machine readable interfaces. This implies that we have to establish and implement methods to reach two major keystones: (#keystone1) create FAIR LOD which is directly connected to the origin database and is interlinked to external repositories, (#keystone2) create research tools – c. f. Little Minions – to make this data usable and findable, by enabling third party software using this resource for further analysis. By implementing #keystone1 and in order to provide the Samian Research Database resource as FAIR LOD, we created a semi-automatic transformation process as well as a CIDOC-CRM and SKOS based ontology, starting from a PostgreSQL database, creating transformation processes to generate CSV and Turtle files using ColdFusion and Python, resulting in a SPARQL endpoint based on a RDF4J triplestore and published with GeoPubby (Thiery, Mees, and Gottwald 2020). In this workflow we also modelled vagueness and uncertainty for relations between e. g. potters and kiln sites using the Academic Meta Tool (AMT). Creating and implementing research software for #keystone2 can be shown using re3dragon (Thiery 2021). The re3dragon tool envisages two aims: (1) publication of an open extendable archaeology related LOD resource catalogue, including authority data, thesauri, controlled vocabularies, gazetteers (e. g. GeoNames, Pleiades), time gazetteers (e. g. ChronOntology, PeriodO), as well as typologies and domain specific resources (e. g. nomisma, Roman Open Data); (2) offering an API for requesting distributed LOD resources providing the resources in a standardised JSON format based on JSKOS. <em>Figure 1: Distribution map of Dressel 6b amphoras and Terra Sigillata from Pisa, generated by combined SPARQL querying of distributed resources</em> Using the former mentioned methods and workflows we created and published 7.869.468 triples and 306.615 instances under a DPPL License (status: 4/12/2020) as well as the underlying ontology as Linked Open Samian Ware to reach #keystone1. On top of that, the relations between historically grown different Samian typologies are semantically modelled in an ontology, and interlinked with Linked Open Samian / Red Slip Ware data. The Ceramic Typologies Ontology Viewer is able to visualise this typology graph displaying semantic connections, e. g. tradition, publisher, generic form, same form, service member, or identical potform properties. The core of the re3dragon API is published on GitHub. This enables the Linked Open Samian Ware data to become reusable and to reach #keystone2. Therefore, this new FAIR and LOUD resource allows also for e. g. geospatial analysis using QGIS and the SPARQLing Unicorn QGIS Plugin, where two distributed LOD resources (e. g. Linked Open Samian Ware and Roman Open Data) can be sparqled and e.g. combined in one distribution map (figure 1). Making modern data dragons LOUD and FAIR has huge implications for archaeological research: combining distributed online resources of completely different find groups (e. g. amphoras and Terra Sigillata) offer entirely new research perspectives. In this case, clear differential markets for contemporaneous goods such as Dressel 6b amphoras (black dots) and Terra Sigillata from Pisa (red dots) are discernable. This opens research questions related to market strategies in the Augustean period. <strong>References</strong> RGZM. 2021. ‘Samian Research’. 2021. http://www.rgzm.de/samian. Thiery, Florian, Mees, Allard, and Gottwald, Dennis. ‘Linked Open Samian Ware Documentation’. 2020. https://rgzm.github.io/samian-lod/doc/. Thiery, Florian. 2021. ‘re3dragon’. 2021. https://github.com/RGZM/re3dragon.