Quantitative Analysis of Coin-Types

Among the American Numismatic Society's current projects is Online Coins of the Rome Empire (OCRE), which is a free, open-access catalog of Roman Imperial Coins.  Each coin type numbered in RIC will be represented with a nomisma URI.  A NUDS XML record will describe the typological attributes of the coin-type, as well as link to associated physical objects in various collections (Mantis, to start).  An early Numishare blog post describes this feature in more detail.  We will be presenting a prototype of OCRE at CAA in March (abstract).  The OCRE project not only provides stable URIs for coin-types, but also a user interface for searching, browsing, and mapping Roman Imperial Coins in the same manner of Mantis.

Since a coin-type record can point to related coins in other collections, Numishare can extract physical attributes of those coins, as well as findspots (if available).  The Solr index, for example, will ingest all of the weights of associated physical coins to ascertain the average weight and standard deviation for a coin-type.  The accuracy of these measurements improves proportionally to the number of coins from which the weights are derived.

Numishare currently supports comparing the average weight of a particular coin type to the average weights of associated facets, e.g., by the same authority, denomination, or material across the entire collection.  Eventually, it will support user-set queries: compare RIC Augustus 410 (a silver denarius) with other silver coins of Augustus and with silver coins of the late 3rd century AD.  These sorts of quantitative analyses will no doubt serve as a great resource to numismatists and ancient historians.

The general distribution of Numishare supports a quantitative analysis tab for coin-type records that have associated weight measurements.

The Kittredge Collection Gets a Facelift

The Kittredge Collection relaunched Sunday evening.  The Kittredge Numismatic Foundation was an early sponsor of Numishare directly after it had been released to the community as an open-source project and a proponent of many of its early features, including the XForms-based backend.  The data has been migrated to NUDS from Encoded Archival Description (for coins) and disseminated with the latest version of Numishare.  The data is still a work in progress; mints point to geonames.org URIs, while materials and object types point to nomisma.org URIs, but much work is left to be done to point other numismatic concepts to unique identifiers.

The Kittredge Collection contains all of the latest mapping and linked open data features detailed in this blog, as well some new additions--particularly the expandable date facet on the browse page that allows the user to select coins by century and decade (example: http://kittredgecollection.org/results?q=%28decade_num%3A1650+OR+decade_num%3A1670+OR+decade_num%3A1690%29).  This feature was ported over from EADitor.

Flickr Image Integration

Major updates have been underway in Numishare development over the last few months, as exhibited by the recent flurry of blog posts.  One of the more recent advances has been in integrating the flickr API into the Numishare administrative back end, enabling users to attach images from that web service to coin metadata records.  The process is fairly straightforward.  The user:

1. Signs up for flickr and requests an API key
2. Inputs the API key into the Numishare settings page and updates the settings
3. Opens a coin record and inserts an obverse or reverse image
4. Pastes a URL of a flickr image into the input box and clicks the "Attach" button

When the user clicks this button, an API lookup is called to receive URLs to available image sizes, and each URL is stored in METS elements embedded into the NUDS XML document.

When the coin is saved and published to the search index (Solr), the thumbnail and medium-sized images are stored so that they can be accessed from the search results page (and, obviously, from the coin record itself).

When clicking on the medium-sized images, the user is directed to the flickr URL for that object, per their terms of service.

Leveraging flickr's service for image storage and retrieval has numerous benefits, especially when a collector or institution may have a large body of image files, but not enough web space on the server on which Numishare is installed or if there is a wish to make just the images accessible through other media.  Flickr is a great alternative Numishare's default image uploading mechanism, Remotemagick, an XML-RPC service which is a front-end to imagemagick that interacts with Orbeon for uploading and resizing images.

Leveraging nomisma to Deliver Controlled Vocabulary Services

With the launch of the nomisma.org Atom feed just a few days ago, I went to work on developing an XForms component which leverages the service to deliver controlled vocabulary terms for ancient mints within the administrative backend of Numishare. Numishare's interface for creating and editing coins already included a connector to geonames.org's APIs for querying modern place names, which I have detailed on the EADitor blog.

The nomisma service operates in similar fashion. A user selects a "nomisma" radio button (versus the other options to query geonames or local controlled vocabulary stored in the Solr index), inputs a search term into a text box, clicks the search button which executes an xforms:submission to query the Atom feed (which populates an xforms:instance), and selects the appropriate option from the select list box, which is formed by each atom:entry returned by the query. An example is pictured below:


The nomisma URI is stored as an attribute in the mint element in the NUDS-XML record so that, upon indexing the record into the search index, a lookup is performed on the RDFa of the nomisma id to extract geographic coordinates, enabling mapping out of the box of ancient mints (in addition to modern mints that are supplied through the geonames service). As noted earlier, findspots are also mappable.


Additionally, if the nomisma RDFa includes a reference to the associated Pleiades place, the Pleiades URI is also stored in the search index, enabling querying of Numishare by that URI.

Code for XForms XBL component

Nomisma.org launches Atom feed

Last week I began development on an Atom feed for the numismatic concepts described on nomisma.org. The feed will be updated nightly with the latest changes to the concepts, so you can be sure to keep abreast of new mints, denominations, hoards, etc.! Like the Atom and KML services on MANTIS, the feed is derived from Solr search results, and is thus queryable with the Lucene syntax. Most importantly, this feed will form the basis for numismatic controlled vocabulary in the backend of Numishare and will ultimately facilitate internationalization of coin collections that use the software by indexing coins based on unique identifiers for typological attributes (e.g., denomination, material) that are independent of the language in which the institution's collection is described.

There is a limited number of fields, so I will list them below.

id: unique identifier of the record
typeof: category of record. values currently include-- hoard, typology_entry, mint, skos:Concept, authority, romanemperor, collection, material, numismaticTerm, term, and denomination
prefLabel: preferred label of record
altLabel: alternate label of record, likely to include other languages
definition: small blurb describing the object
pos: GML-compliant geographic coordinates
burial_start: integer referring to terminus post quem (of a hoard)
burial_end: integer referring to terminus ante quem (of a hoard)
fulltext: text anywhere in record

Examples
http://nomisma.org/feed/?q=typeof:mint+attica - Mints in Attica
http://nomisma.org/feed/?q=burial_start:\-240 - terminus post quem of 240 B.C.

The feed contains links to the next and last pages so that it is possible to easily page through it. The page number is appended after feed/ in the URL, like so:

http://nomisma.org/feed/2/?q=*:*

Many of the entries in the feed also include geographic coordinates, and thus Google Maps is capable of rendering it in map form.

I will follow this post up with another about the feed's interaction with the XForms backend in Numishare, and how this will contribute to name authority.

Numishare's Improved Data Model, Applied to Findspots

As I mentioned in the previous blog post, we are re-envisioning Numishare's underlying data model. The three sites that currently use Numishare in one form or another (University of Virginia Art Museum, Kittredge Collection, ANS's Mantis) are built on an adaptation of Encoded Archival Description, an XML standard common to archival collections, to numismatics. The new model is a numismatic-specific ontology that includes some museum collection types of fields, and is greatly influenced by existing XML standards. In fact, digital images are described in METS.

This new data model, let's call it NUDS-XML, also draws inspiration from linked open data initiatives, best illustrated by two types of records that can be described in Numishare.

The previous version of Numishare assumed that all records represented physical objects. Certainly the new NUDS-XML allows this type of record as well. The other type of record to be introduced is a conceptual object. This is, to say, an XML document that describes a coin-type. It contains, almost exclusively, typological metadata. This includes fields such as types and legends, authority and issuer, mint, material, and denomination. Unlike a record which describes a physical object, it does not contain die axis, weight or other dimsensions, nor does it contain information about provenience, owner, or repository. These fields are distinct to physical objects, not coin-types.

Among planned projects at the American Numismatic Society is an open access catalog of Roman imperial coins. There are tens of thousands of coin-types over several centuries, beginning with Augustus. The ANS does not own a physical representation of each conceptual object, but may own duplicates for other coin-types. The goal is to create a NUDS-XML record for every Roman imperial coin-type, and enable those records to point to URIs of associated physical objects in Mantis (or other digital numismatic collections).

In order to avoid duplication of typological metadata, physical record types in Numishare contain a URI reference to the source conceptual record rather than chunks of XML. Upon rendering and indexing into Solr the physical object record, the URI will be parsed by the XML/XSLT processor (in this case, Apache Cocoon) and the data scraped directly from the source typological record.

Examples below:

Above, a record for a Roman imperial coin-type

Above, a physical object record linked to the coin-type.

We can leverage the LODness of this new data model to render findspots for a coin-type. The encoding of findspots in NUDS-XML is pretty rudimentary thus far. A simple block of GML is embedded into an element called findspot. Ultimately, findspots can also refer to resources available at URIs, and geographical metadata may be scraped from external sources (like nomisma.org).

In any case, when a conceptual record is indexed into Solr, the indexing script scrapes the record's associated physical objects' NUDS-XML for GML coordinates and indexes them for rendering in an OpenLayers map layer. [The layer is derived from a Solr-to-KML transformation that has been detailed in an earlier blog post.] In Numishare, when a physical object's findspot is added or updated, and that object's typology is derived from a coin-type record, that coin-type record is reindexed in Solr so that changes to the map are apparent immediately.


These maps are especially valuable to economic historians for analyzing the distribution of a particular coin-type over space (and eventually time, when we introduce temporal mapping). One can visualize trade networks by the distribution of currency.

Visual Themes in Numishare

I've been busy over the last few weeks on seriously revamping Numishare's code trunk. We're moving toward a numismatics-specific XML ontology based on the NUDS fields list, which draws much inspiration from existing standards like VRA Core, EAD, and TEI, but also incorporates tenets of linked open data. I'll discuss NUDS-XML in greater detail in a future blog post.

As part of this major revision to Numishare (which I hope to officially release as Numishare 1.0 later this fall) is a simplified theming interface. One of the drawbacks to the application when it was first released about two years ago is that it required XSLT and general web development knowledge in order to customize the front-end user interface. While direct customization of code can still be done by a savvy developer in the current version, much of the theming is being moved into the administrative interface, with an XForms application that enables the user to control the visual design of the public site with an intuitive web interface that will function much like Blogger's own interface for customizing this or other blogs. This feature is vital in the encouragement of institutions and collectors to adopt Numishare as their publishing platform. After the initial deployment of Numishare's required applications onto a server (which takes a sys admin about 15 minutes), no other serious technical investment is required of the Numishare administrator to begin publishing coins since it requires no programming expertise to visually distinguish Numishare-based sites from one another.

jQuery UI theme

Object display page layout

The interface will enable the user to specify which jQuery UI theme to use (all pre-packaged themes are available to choose from), as well as other colors, fonts, background images, banner images, etc. There will be several page layouts to choose. These visual configurations are stored in an XML file that is edited with an XForms web form. So far, the jQuery UI theme and object display page layouts have been implemented, and I plan to implement the remainder of the theme-adjusting interface will be completed in the coming weeks.