Thursday, April 9, 2015

From 0 to 60 on SPARQL queries in 50 minutes

On Wednesday, May 13, at 10 AM EDT, I will be giving a free webinar sponsored by the Dublin Core Metadata Initiative and the Association for Information Science & Technology.

This webinar provides an introduction to SPARQL, a query language for RDF. Users will gain hands on experience crafting queries, starting simply, but evolving in complexity. These queries will focus on coinage data in the SPARQL endpoint hosted by numismatic concepts defined in a SKOS-based thesaurus and physical specimens from three major museum collections (American Numismatic Society, British Museum, and Münzkabinett of the Staatliche Museen zu Berlin) linked to these concepts. Results generated from these queries in the form of CSV may be imported directly into Google Fusion Tables for immediate visualization in the form of charts and maps.

This webinar was first presented as a training session in the LODLAM Training Day at SemTech2014. I will cover the basics of an RDF triple, but the presentation assumes some baseline understanding of linked data. The SPARQL queries will begin simply and build in complexity, culminating in spatial queries.

Sign up at 


Wednesday, March 25, 2015

ANS Partners with HathiTrust for Open Access Publications

In a sweeping effort to make its older and out-of‐print publications available to the public as Open Access, The American Numismatic Society has partnered with HathiTrust ( As a result of this partnership scans of nearly 550 ANS titles – including the American Journal of Numismatics, Numismatic Literature, Numismatic Notes and Monographs, and stand-­alone monographs have become fully readable and downloadable to anyone who wants them under a Creative Commons, non-­commercial, attribution, share-­alike license. This means that these ANS publications can be used for personal reading, research, and academic publication just so long as the ANS is cited as the source. Titles currently in the public domain – already have a home on HathiTrust. These volumes were OCR-scanned as part of the Google Books project.

HathiTrust, founded in 2008 by the member universities of the Committee on Institutional Cooperation and the University of California, is a large, collaborative repository of digital content from research libraries and publishers that includes content digitized by Google Books and Internet Archive and Microsoft. Millions of volumes are available via HathiTrust’s website ( The entire repository can be full-text searched.

The ANS publications have been organized into a single collection for easy searching:;c=1850525919.

Thursday, February 12, 2015

New framework has been released

After much work, the new framework has been launched into production. Not only is this a major architecture migration (moving the public UI from Apache Cocoon into Orbeon), but a data migration. We have implemented a new data model for IDs that conforms to the Nomisma ontology that Karsten Tolle has been working on for at least two years. IDs have a more stable system of classes that will improve the predictability of queries. There are presently 16 classes by which IDs are defined--most of them in the nmo: ( namespace, but we are using the W3C Organziation ontology for expressing roles of people and organizations (under foaf:). The ontology is still evolving, but has a carefully curated set of properties and classes that pertain to numismatics. Certain URIs (like nm:mint), will never again be used simultaneously as classes and properties. In fact, all of the URIs that were used as classes and properties have been made instances of nmo:NumismaticTerm. Instances of mints (like Rome or Athens) are an nmo:Mint, and nmo:hasMint is the property to use for linking a coin or coin type to a mint URI. The ontology and data conform to standards established by the semantic web and computer science communities.

Data dumps from museum collections (like the ANS and Berlin) have been migrated into the Nomisma ontology, as have RDF exports from online type corpora, like OCRE and CRRO. This involved updating Numishare's code to export in the new ontology (see for example), as well as update SPARQL queries and the XSLT for reading latitude and longitude in the new model for mints. Mints are now reckoned as concepts (carrying the skos:Concept class, as well as nmo:Mint) that may or may not have a spatial feature, linked with geo:location. The object links by the geo:location is a geo:SpatialThing which may either have a latitude and longitude or have geoJSON encapsulated in the osgeo:asGeoJson property. Complex shapes, represented as geoJSON, can be drawn in Nomisma's XForms-based editing interface (powered by Orbeon). geoJSON objects created in OpenLayers in the editing interface are extracted by Javascript and incorporated into the XForms engine.

The new features of this framework are almost two numerous to mention, but here is a synopsis:

  • IDs are available in their native RDF/XML, but also serialized into Turtle and JSON-LD. IDs for regions that may contain complex geoJSON polygons are exported in geoJSON-LD. These serializations are linked from the ID page. Data dumps of all IDs are available in these three serializations as well.
  • Spatial queries are supported by extending Fuseki to interact with a Solr index.
  • Much improved browse interface allows for additional filtering by roles of people/organizations and sorting. These filters can be applied to the Atom feed as well.
  • Content negotiation is supported for IDs, the SPARQL endpoint, and the browse page. See for more information about interacting with IDs and Solr. The SPARQL endpoint supports text/html, text/csv, text/plain, application/sparql-results+json, and application/sparql-results+xml.
  • RIC and RRC ids have been deprecated by Nomisma, as OCRE and CRRO maintain up-to-date and better quality versions. HTTP 303 See Other redirects are established for any ID that contains a dcterms:isReplacedBy property that links to something else. See
  • We have begun documenting the model and example SPARQL queries. The documentation will evolve to become more comprehensive in the coming months.
  • The system in general is far more stable and efficient now that RDF/XML has replaced XHTML documents. It reduces the need for additional transformation when delivering web services. More than 90% of HTTP requests for Nomisma content comes from machines (about 30,000 per day).

Thursday, January 15, 2015

Coinage of the Roman Republic Online: Something for Roman Numismatists to “CRRO” about

Today, in collaboration with the British Museum and the Münzkabinett of the Staatliche Museen zu Berlin, the ANS launches another major new tool to aid in the identification, research and cataloging of the coins of the ancient world. 

Coinage of the Roman Republic Online (CRRO) continues the precedent set by Online Coins of the Roman Empire (OCRE) in presenting, in an easily searchable form, all the varieties of the coinage issued in the Roman Republic. Six online collections containing over 20,000 specimens of Roman Republican coinage spread across 2,300 coin types, in addition to hundreds of hoards from Coin Hoard of the Roman Republic (CHRR) and additional individual findspots provided by Berlin are now available for research. 

The site presents a basic description of each published variety based on Michael Crawford’s 1974 publication Roman Republican Coinage (RRC), which remains the primary typology used for the identification of Roman Republican coin types. Since its publication there have been significant revisions to the dating of the series following the discovery of new hoards, but no attempt has been made to reflect these, or to make any other amendments to the published typology at this stage. 

The descriptions are based on the typology set out in RRC, but have been modified to meet the standards of the British Museum’s collection management system by Eleanor Ghey and Ian Leins. These were previously published in Ghey and Leins 2010, which forms an update to the 1910 catalogue of the collection by Grueber. Additional types not in the British Museum’s collection were added to this database by Richard Witschonke of the ANS. 

Many of these coin types are linked to specimens present in the British Museum’s collection, Münzkabinett of the Staatliche Museen zu Berlin, the ANS, and elsewhere, and where available, to images. Searches are made straightforward through a series of facets, presented in a way that will already be familiar to users of other ANS search tools. Traditional searches of familiar numismatic categories such as obverse and reverse legends and types are provided, as well as the ability to search by deity, in the hope that CRRO will provide an identification tool useful to collectors, dealers, curators, and field archaeologists. Researchers can now list all coin types found within a country and any regional division below the country (E.g., Liguria, down to the town or city). 

ANS database developer, Ethan Gruber, says that, "like OCRE and all of our other digital projects at the ANS, CRRO uses Linked Open Data methodologies to aggregate information from disparate institutions and present the information in an interface available in more than 10 languages with advanced mapping and metrical analysis features. CRRO is a fully functional research portal for Roman Republican numismatics." 

The ANS acknowledges the contribution of Michael Crawford to the project, and also thanks Michael Sharp of Cambridge University Press for allowing us to use the numbering system of Roman Republican Coinage. 

For further information contact Joanne Isaac or call (212) 571 4470 ext. 112.

Tuesday, January 6, 2015

Berlin Joins OCRE Project

We are kicking off the new year with a major breakthrough in the Online Coins of the Roman Empire project. Yesterday, I received a data dump of LIDO/XML of Roman imperial coins from the Berlin Münzkabinett, for which I wrote two PHP scripts: the first to create a concordance between their reference field and coin type URIs in OCRE, and the second to iterate through their dump to create RDF that I just ingested into's SPARQL endpoint. Nearly all of Berlin's coins are photographed, and all contain axes, weights, and diameters which are available for metrical analysis through OCRE visualization interface (

In the week before the holiday, we completed RIC Volume IV, covering all Roman emperors through Uranius Antoninus (A.D. 254). There are now more than 21,000 coin types available in OCRE, with physical specimens from the British Museum and Berlin now linked in through Uranius. We are waiting on some updates from Mantis in order to link in ANS coins for Trebonianus Gallus, Trajan Decius, and a few others. We also expect a batch of photographs for several thousand coins in the coming weeks.

We should be moving into RIC V by next month.

edit (12 Jan. 2015):

All of Berlin's coins in OCRE come with photographs, but the current number (3,620) is not representative of all of Berlin's Roman imperial coins. Only those which have been photographed are published to the database online.

Wednesday, December 17, 2014

Near term progress in digital numismatics

Looking Back

As we close out 2014, we can reflect on a tremendous amount of progress we have made with respect to and other digital numismatic projects at the American Numismatic Society. Numishare's front end has been migrated from Cocoon to Orbeon, which will enable a wider variety of current and future web standards, and the user interface was migrated into Bootstrap 3 last spring. The new version of Mantis was launched a few months ago, immediately following the release of a new project, The Art of Devastation, which is a type corpus of World War I medals. The first of the Edward T. Newell Greek numismatic research notebooks have gone online, annotated to link to other resources (monographs, coins in the ANS collection, and other researchers) by means of LOD technologies. The new version of the ANS archives, Archer, has gone online, employing SPARQL to link to another new project, the ANS Biographies (a production installation of EAC-CPF software, xEAC). In OCRE, we have completed volume IV of RIC, from Septimius Severus to Uranius Antoninus. More than 12,000 coins from the British Museum have been ingested into the Nomisma triplestore to be made available in OCRE (with many thanks to Eleanor Ghey from the BM for providing data dumps in spreadsheets that have allowed me to create a concordance between their coins in OCRE URIs). The new Bootstrap 3 version of OCRE launched into production last February, the first of the Numishare projects migrated into that stylistic framework (therefore, enabling out-of-the-box scaling for mobile devices), and in late March of 2014, we received $300,000 from the National Endowment for the Humanities to complete the project over the next three years. Finally, much progress has been made in the development of a formal RDF ontology for numismatics, in conjunction with an architectural re-write of, which has been in development for much of the year.

Looking Forward

We are going to be making at least as much progress in 2015 as 2014, especially in the first few months of the year. The new framework will be released by the end of January. It will be fully compliant to the latest standards and protocols for a linked data publication framework. The data model for IDs will be revised significantly. SKOS will play a much larger role in linking instances together (via skos:broader), and the instances will conform to formal classes from the Nomisma ontology. The editing interface for concepts will be opened up to a wider editing team, and I foresee many more URIs minted this year, especially outside the realm of ancient numismatics. There is a large demand for greater representation of Medieval and Islamic URIs. The editing interface includes improved lookup mechanisms for linking Nomisma concepts to matching terms in other vocabulary systems, like VIAF and the Getty thesauri.

The main bottleneck for the release of the new version of Nomisma lies in the creation of URIs for Roman Republican moneyers. RRC and IGCH URIs are going to be spun off into separate projects, maintained by specialists are are focused on the curation of those datasets. As a result, the existing RRC URIs in Nomisma must redirect to URIs in a new domain name. Additionally, RRC URIs are used in production in several different projects, so those projects must transition to the new RRC Online URIs before the URIs are deprecated in the namespace. Before RRC Online can launch, the Republican moneyers must have URIs in Nomisma. I expect to have the list verified by the end of the week so that we can move forward with publishing the moneyers in Nomisma either by this Friday or the first week of January. RRC Online (which will function exactly like OCRE, but focused on Roman Republican coinage) will launch soon after. We already have more than 10,000 coins from  the ANS and British Museum ready to be linked into RRC Online, in addition to several hundred coins from The University of Virginia Art Museum, Virginia Museum of Fine Arts, and University College Dublin. After the launch of RRC Online, we will move the new version of Nomisma into production by the end of January. By the time we meet in April in Berlin to discuss the Online Greek Corpus and Poland to discuss the European Coin Find Network, we should have transitioned all projects to use the new Nomisma ontology, which Karsten Tolle has been working on over the last one to two years. A draft of the Nomisma documentation should be available in time for these meetings.

We have a number of longer term Greek numismatic projects coming down the pike. As part of the Online Greek Corpus, we are going to work on standardizing Seleucid and Alexandrian types within the ANS database, as well as work on improving IGCH, which will function as a standalone Greek coin hoard research tool, much like Coin Hoards of the Roman Republic. The digital IGCH will serve as an important bridge between Greek coins in the ANS collection and associated bibliographic references. We hope to show serious progress with respect to Greek projects in time for the INC meeting in Taormina in late September.

Finally, over the course of 2015 and extending a few years into the future, we are going to work on systematically cleaning up the ANS collection database, linking denominations, materials, people, etc. to URIs in Nomisma, the Getty thesauri, VIAF, etc. whenever applicable. This will dramatically improve the usefulness of Mantis, which is often limited due to inconsistency in data entry and utter lack of controlled vocabulary. Furthermore, we are going to work on improving the bibliographic references, making it easier to traverse from Mantis to Donum (the ANS library catalog), Worldcat, JSTOR, etc. to access further information. Mantis will grow into a more useful numismatic research portal over time.

Tuesday, December 9, 2014

Extending Nomisma for spatial queries

I have recently worked on extending the geographic query functionality in the new Nomisma prototype. It took a few days of fiddling around and testing, but it was altogether a painless operation. First it required reading the (excellent) spatial query documentation for Apache Fuseki, which is the SPARQL endpoint that we have been using in Nomisma for nearly two years. I actually had not upgraded Fuseki since launching it into production in the early months of 2013, and so I had to update from 0.2 to 1.1 across the board in order to enable spatial queries--on the Nomisma production server, on the American Numismatic Society production server (Fuseki powers the interlinking of the Society's archival records in Archer), and on my two development machines at home.

Fuseki's configuration can be extended to use Lucene or Solr as the spatial index. The latter made a lot of sense because Solr is already an integral part of the architecture of most of our digital projects. The Solr index in Nomisma powers the basic facet-based search/browse interface and the Atom feed. I found an older email on the Jena list with an example configuration TTL file that I was able to modify.

After successfully configuring the spatial index, I initially learned that I was not able to use my current index for extending Fuseki. That is because only main Nomisma concepts are indexed, and not the geo:SpatialThing objects associated with mints and regions. The browse interface would be confusing if you received results for both nm:rome and nm:rome#this, the geographic feature associated with the concept of the mint of Rome. As a result, I spun up a new index for storing the URIs and coordinates for the geo:SpatialThings only, and this facilitated spatial queries that delivered results that I expected.

This is a dramatic leap forward in the types of geographic queries we can do in Nomisma, as we can get query results within a bounding box or within a certain distance of a point. Once we begin connecting larger numbers of coins with findspots into the system, we'll be able to do heatmaps showing geographic distribution and a variety of other visualizations. If we ingest other forms of GIS data, such as roads, springs, shrines, etc., we can query for hoards and finds within X meters of the geographic feature.

The example below is a query that will get mints within 50 km of Athens (by giving the lat and long of the city).

   ?loc spatial:nearby (37.974722 23.7225 50 'km') .
   ?mint geo:location ?loc ;
         skos:prefLabel ?label .
  FILTER langMatches (lang(?label), 'en')

You can test it yourself in the Nomisma prototype.