Roman Republican Die Project: Nomisma LOD models + IIIF annotation for die studies

By now, you might have heard of the launch of the Roman Republican Die Project (RRDP), overseen by Liv Yarrow and Lucia Carbone, and technically organized/developed by myself. This project represents a leap forward into a new Linked Open Data approach to numismatic die studies that had not yet been implemented in the Nomisma.org ecosystem. RRDP consists of several interlinked databases that form a cohesive research platform for Roman Republican die links, based on the massive accumulation of Richard Schaefer's coin cards and binders we published to Archer earlier this summer. The prototype for RRDP includes the dies and annotated coins only for RRC 15/1a and 15/1b so far, but we will expand to include all Republican types over the next few years. Here is a summary of the individual components that comprise RRDP.

• The RRDP stand-alone site where all of the die URIs will be minted. Each die record will include a network graph and table of links and numeric counts for the die to the related obverse/reverse dies, as well as the obverse or reverse images that have been annotated (see IIIF annotation, below) with that die ID (the linkage is more precisely image URL->coin->obverse/reverse node->die ID).
• Coinage of the Roman Republic Online will probably serve as the primary entry point to die research on the type level. CRRO has been extended to query the Nomisma.org SPARQL endpoint in order to read a list of die combinations and numeric counts (based on the total number of annotated coins so far, so this number will evolve as we continue to enter data!) and a network graph of obverse and reverse die links. RRC 15/1b has the most extensive graph of the two subtypes annotated in the prototype. You can click from these graphs and tables to view the record and visualizations for individual dies in the RRDP platform.
  

  

  Graph for RRC 15/1b
  

  
  
  
• The ANS has launched a stand-alone database of auction catalog materials or collections that are not yet contributors in the Nomisma.org LOD ecosystem. A sort of "mirror" of the ANS database, MANTIS, SITNAM is a Numishare site with identical functionality intended, at the moment, to hold coins from Schaefer's clippings. It will eventually be used to publish private materials ad hoc for other digital aggregation projects. Like MANTIS, the numismatic RDF for SITNAM is exported into Nomisma.org's SPARQL endpoint, making these coins available in CRRO in the same manner as other collections. The coverage of RRC 15/1b has grown about 500% with the inclusion of Schaefer's binders. There are approximately 300,000 Republican coins in Schaefer's research materials, which will dramatically increase the coverage in CRRO (currently 50,000 coins from 40 museums or archaeological datasets). Many of Schaefer's coins include measurements, such as weight, that will enhance the research value of CRRO even beyond the die linking.
• The die links themselves. The die IDs are not stored within the metadata for an individual specimen, but rather stand separately in a Nomisma model that integrates some properties from CIDOC-CRM that will enable multiple scholars to make different die attributions about the same coins, with each scholar's attributions bound to a Named Graph when posted into the Nomisma SPARQL endpoint. For example: 

@prefix nmo: <http://nomisma.org/ontology#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix crm: <http://www.cidoc-crm.org/cidoc-crm/> .
@prefix void: <http://rdfs.org/ns/void#> .

<http://numismatics.org/collection/1969.83.3>
  a <http://nomisma.org/ontology#NumismaticObject> ;
  nmo:hasObverse [ nmo:hasDie [
      rdf:value <http://numismatics.org/rrdp/id/rrc-15.1.o.1> ;
      crm:P141i_was_assigned_by [
        a crm:E13_Attribute_Assignment ;
        crm:P14_carried_out_by <http://nomisma.org/editor/rschaefer>
      ]
    ] ] ;
  nmo:hasReverse [ nmo:hasDie [
      rdf:value <http://numismatics.org/rrdp/id/rrc-15.1.r.1> ;
      crm:P141i_was_assigned_by [
        a crm:E13_Attribute_Assignment ;
        crm:P14_carried_out_by <http://nomisma.org/editor/rschaefer>
      ]
    ] ] ;
  void:inDataset <http://numismatics.org/rrdp/> .

The above TTL binds an existing ANS URI http://numismatics.org/collection/1969.83.3 to an obverse and reverse with an nmo:hasDie blank node with an attribute assignment linking to a die URI attested by Schaefer. This annotation would be posted to the SPARQL endpoint to a Named Graph for http://nomisma.org/editor/rschaefer. Numishare has been extended submit SPARQL queries to Nomisma for die relationships for the type or individual die level. The network visualization uses d3plus (a simplified layer for d3js); the SPARQL results are serialized into JSON for display in d3plus.

It is important to note that the canonical coin URI is stored in our specimen spreadsheet so that duplicate coins are not published to SITNAM. Therefore, when generating the die link RDF, we are able to make statements about existing coin URIs at a Named Graph that do not interfere with the collection-published RDF from the institution that contributed the data into Nomisma. For example, RRDP RRC 15/1 obverse die G will include two coins from SITNAM and one from the ANS, because Schaefer has made a statement about an ANS coin, and we can rely on the ANS's high resolution IIIF images rather than the scans of paper cut-outs.

Schaefer RRC 15/1 Obverse G

IIIF Annotation

It is important to preserve the Schaefer binders as archival research documents in their own right, complete with notes and labels, and so it will be possible to navigate from a specimen in SITNAM to its annotated binder page in Archer.

Since these binders have already been published to Archer, with the images served through our IIIF image server (and therefore, each binder has a IIIF manifest), I have deployed Simple Annotation Server, which is a bootstrapped version of Mirador connected to the latest version of Apache Solr (as the annotation store), running as a Tomcat webapp. Unique IDs for binder specimens are generated in a Google sheet, and then the obverse and reverse images for that coin are annotated with the ID appended with _obv or _rev. 

Annotating individual coins via IIIF

When processing the specimen spreadsheet for publication into SITNAM, my script reads the Solr index and extracts the annotation location and dimensions from the Web Annotation JSON-LD in order to store a IIIF URL pattern for the jpeg for each side of the coin, e.g., http://images.numismatics.org/archivesimages%2Farchive%2Fschaefer.rrdp.b01_0098.jpg/285,1332,476,515/full/0/default.jpg (for http://numismatics.org/sitnam/id/87c989a1). SITNAM links back to the relevant binder page in Archer. Eventually, the Mirador viewer in Archer itself will be plugged into these annotations in the front end, making it possible to navigate from binder pages back to SITNAM or, if applicable, the canonical URI for that coin in its home collection database.

Future Plans

RRDP has received $115,000 or so from the Arete Foundation to complete the project over the next few years. The ANS is going to hire a full-time employee to work on data entry and annotation, and as more coins go into the system, the more accurate and complete the network graphs and metrical analyses become. 

While the current visualizations in CRRO and RRDP are based on die->coin->type relationships alone, it is possible to increase the complexity of these SPARQL queries to dive into the descriptions of the types or other attributes of coins (for example, hoards or findspots). So it will be possible to display die linkages not just for a type, but, for example, all denarii minted from 100-75 BC or all types issued by the same moneyer, or die links for only those coins found in Britain (as recorded in the Portable Antiquities Scheme). As we begin to accumulate more data in RRDP (beyond RRC 15/1), I will begin providing more research examples and building out more sophisticated query interfaces in the RRDP platform. This is really just the tip of the iceberg for what will be possible in this new LOD-oriented die study infrastructure.