BBTalk
BBTalk is the software component that manages the functions of connecting specialist thesauri into the federated system, as well as submitting new terms and changes in the BBT. It is used as an alignment tool by local thesauri maintainers wishing to link and publish their thesauri through the BBT thesauri federation. It also serves as a communication system, supporting discussions between the curators of the BBT and its other users.
Mapping local thesauri to the BBT
Local thesauri maintainers align their thesauri to the BBT. This is achieved by linking high-level terms of individual thesauri to the appropriate BBT term and declaring the relation that holds between them.
Figure: Creating and managing connections
Data enrichment & development scenario
In the event that end-users cannot find an appropriate BBT-term to map one’s terms onto, a process of discussing the extension and expansion of the BBT itself gets launched. In the rest of this section, the methodology for managing these discussions will be presented.
Assuming that parts of some specialist thesaurus do not integrate well with BBT, then a proposal to introduce a new facet or a new term within one of BBT’s facets may be put forth by the person implementing the mapping. It is possible that the BBT underspecifies conceptual distinctions that are particularly prominent in a given thesaurus. Integrating such a thesaurus with the BBT might call for changes in the overall scope of the BBT.
Aside proposing new terms, end-users faced with this situation can propose to split (or otherwise modify) BBT facets and terms. Conversely, there might be reason to broaden the scope of the BBT, in which case, part of its structure may become less relevant. It is possible then, that end-users request for facets/hierarchies to be deleted, merged, or otherwise modified. This is part of the open-ended strategy assumed for the BBT.
Figure: Creating and managing submissions
The submissions (i.e. proposals to implement changes to the BBT) are discussed by interested parties; that is, the person submitting the proposal, the team managing the BBT and thesauri maintainers whose thesauri have been integrated with the BBT and can be affected if the proposed change is implemented. Domain experts in their respective fields can also be invited to participate in the discussion through BBTalk.
Decisions for or against a specific request to change the structure of BBT are reached by vote. Implementing changes in the BBT results in new releases thereof; BBTalk keeps track of all the different releases and the history of submissions, plus it serves as a record of the relevant discussions related to the evolution of the metathesaurus.
The BBT-Browser
Following the linking process, said local thesauri can be searched together. The browsing of these rich interconnections is supported by the BBT-Browser, a SKOS vocabulary browser, such as the SKOSMOS system deployed by the ACDH Vocabs services (https://vocabs.dariah.eu/). Skosmos offers browsing of vocabularies with structured concept displays and visualization of concept hierarchies. Each concept has a unique and resolvable URI. End-users can access the connected resources through the BBT-Browser service, as demonstrated in previous figure ("Creating and managing connections").
The BBT-Browser is responsible for hosting and providing access to the current version the BBT. It provides consistent identification (LOD identification) for all terms of the BBT, in order to be referenced by the local thesauri. Its current version can be accessed by clicking the link: https://vocabs.dariah.eu/bbt.
Figure: Browsing the BBT federation of thesauri through the BBT-Browser
