Pleiades: News and Views

The new OSM editor is a pleasure to use and I've been inspired to fix up my neighborhood a bit. It was cool to see these historic homes (designated Fort Collins landmarks, in fact) pop up in MapBox just minutes after I submitted them.

Google Maps, on the other hand, has no historic homes and a rather outdated and (sadly) never to be realized development proposal in the neighborhood. Fixing Google's map for free is not high on my list of priorities.

Next, I'd like to finally get some Pleiades-related data into the OpenHistoricalMap sandbox.

I'm pretty sure this will be the last post to this blog. I'm not going to delete it but I think I should advertise the fact that I no longer use it to communicate my thoughts about digital humanities, Roman pottery, etc. Recently, I've been using Google+, Twitter, and (for better or for worse) Facebook for that purpose. My guess is I'll find reasons to piggy-back on other people's blog as a guest contributor so I thank you in advance should you ever give me that opportunity...

In addition to our ubiquitous "Live Search", Pleiades provides a sophisticated "Advanced Search" form for more complicated queries. Here are some tips for using it.

I'm collaborating with other folks both in and outside ISAW on a variety of digital scholarly projects in which Linked Open Data is playing a big role. We're using the Resource Description Framework (RDF) to provide descriptive information for, and make cross-project assertions about, a variety of entities of interest and the data associated with them (places, people, themes/subjects, creative works, bibliographic items, and manuscripts and other text-bearing objects). So, for example, I can produce the following assertions in RDF (using the Terse RDF Triple Language, or TuRTLe):

<http://syriaca.org/place/45> a <http://geovocab.org/spatial#Feature> ;
  rdfs:label "Serugh" ;
  rdfs:comment "An ancient city where Jacob of Serugh was bishop."@en ;
  foaf:primaryTopicOf <http://en.wikipedia.org/wiki/Suruç> ;
  owl:sameAs <http://pleiades.stoa.org/places/658405#this> .

This means: 'There's a resource identified with the Uniform Resource Identifier (URI) "http://syriaca.org/place/45" about which the following is asserted:

• it is a "Feature" as defined in the NeoGeo Spatial Ontology;
• the human-readable version of its name is "Serugh";
• a human-readable description (in the English language) of it is "An ancient city where Jacob of Serugh was bishop.";
• it is the primary topic of a document that is identified by the URI "http://en.wikipedia.org/wiki/Suruç"; and
• it is the same resource as that identified by another URI: "http://pleiades.stoa.org/places/658405#this".'

(Folks familiar with what Sean Gillies has done for the Pleiades RDF will recognize my debt to him in the what proceeds.)

But there are plenty of cases in which just issuing a couple of triples to encode an assertion about something isn't sufficient; we need to be able to assign responsibility/origin for those assertions and to link them to supporting argument and evidence (i.e., standard scholarly citation practice). For this purpose, we're very pleased by the Open Annotation Collaboration, whose Open Annotation Data Model was recently updated and expanded in the form of a W3C Community Draft (8 February 2013) (the participants in Pelagios use basic OAC annotations to assert geographic relationships between their data and Pleiades places).


A basic OADM annotation uses a series of RDF triples to link together a "target" (the thing you want to make an assertion about) and a "body" (the content of your assertion). You can think of them as footnotes. The "target" is the range of text after which you put your footnote number (only in OADM you can add a footnote to any real, conceptual, or digital thing you can identify) and the "body" is the content of the footnote itself. The OADM draft formally explains this structure in section 2.1. This lets me add an annotation to the resource from our example above (the ancient city of Serugh) by using the URI "http://syriaca.org/place/45" as the target of an annotation) thus:

<http://syriaca.org/place/45/anno/desc6> a oa:Annotation ;
  oa:hasBody <http://syriaca.org/place/45/anno/desc6/body> ;
  oa:hasTarget <http://syriaca.org/place/45> ;
  oa:motivatedBy oa:describing ;
  oa:annotatedBy <http://syriaca.org/editors.xml#tcarlson> ;
  oa:annotatedAt "2013-04-03T00:00:01Z" ;
  oa:serializedBy <https://github.com/paregorios/srpdemo1/blob/master/xsl/place2ttl.xsl> ;
  oa:serializedAt "2013-04-17T13:35:05.771-05:00" .

<http://syriaca.org/place/45/anno/desc6/body> a cnt:ContentAsText, dctypes:Text ;
  cnt:chars "an ancient town, formerly located near Sarug."@en ;
  dc:format "text/plain" ;

I hope you'll forgive me for not spelling that all out in plain text, as all the syntax and terms are explained in the OADM. What I'm concerned about in this blog post is really what the OADM doesn't explicitly tell me how to do, namely: show that the annotation body is actually a quotation from a published book. The verb oa:annotatedBy lets me indicate that the annotation itself was made (i.e., the footnote was written) by a resource identified by the URI "http://syriaca.org/editors.xml#tcarlson". If I'd given you a few more triples, you could have figured out that that resource is a real person named Thomas Carlson, who is one of the editors working on the Syriac Reference Portal project. But how do I indicate (as he very much wants to do because he's a responsible scholar and has no interest in plagiarizing anyone) that he's deliberately quoting a book called The Scattered Pearls: A History of Syriac Literature and Sciences? Here's what I came up with (using terms from Citation Typing Ontology and the DCMI Metadata Terms):

<http://syriaca.org/place/45/anno/desc7/body> a cnt:ContentAsText, dctypes:Text ;
  cnt:chars "a small town in the Mudar territory, between Ḥarran and Jarabulus. [Modern name, Suruç (tr.)]"@en ;
  dc:format "text/plain" ;
  cito:citesAsSourceDocument <http://www.worldcat.org/oclc/255043315> ;
  dcterms:biblographicCitation  "The Scattered Pearls: A History of Syriac Literature and Sciences, p. 558"@en .

The addition of the triple containing cito:citesAsSourceDocument lets me make a machine-actionable link to the additional structured bibliographic data about the book that's available at Worldcat (but it doesn't say anything about page numbers!). The addition of the triple containing dcterms:bibliographicCitation lets me provide a human-readable citation.

I'd love to have feedback on this approach from folks in the OAC, CITO, DCTERMS, and general linked data communities. Could I do better? Should I do something differently?

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The SRP team is currently evaluating a sample batch of such annotations, which you're also welcome to view. The RDF can be found here. These files are generated from the TEI XML here using the XSLT here.

If the Pleiades website is slow or offline, check http://pleiades-site-status.tumblr.com/ for the reasons why

Pleiades has a new associate editor!

Explanatory notes have been added for some existing entries, and several areas that were marked "to be added" have now been completed.

The latest guidance how to add new name resources to Pleiades.

Let's make more links from Pleiades to monuments and sites in OpenStreetMap.

Direct place-to-place relationships allowing the construction of geographic hierarchies and networks. Rivers to seas, roads to towns, towns to ethnic regions or provinces.

Grouping our how-tos in a more useful way.

Our first help document on the subject!

We are soliciting comments on a newly-drafted "Reviewers' Guide", which we think also will be of use to everyone interested in adding content to Pleiades.

We had so much fun working on mountains last week, let's do it again! 2pm UTC on Thursday, 24 January 2013.

Come summit with us! The focus of our next mapping party (formerly "hackfests") will be mountains and mountain ranges.

Have you heard of Flickr, the photo sharing site with Creative Commons licensing options and a great API for access to photos and metadata? I ask because our collective attention span is so short that I wonder whether our memory hasn't been similarly impaired. Flickr has weathered harsh criticism from former employees and speculation about the number of days until Yahoo kills it, and has regained for now the fickle favor of the web. A year ago, I wrote about Flickr's extra love for Pleiades machine tags: http://sgillies.net/blog/1103/flickr-support-for-ancient-world-places. I'm going to take the opportunity of Flickr's comeback to write about what's new in tagging photos with Pleiades places.

Flickr reports almost 7000 photos with pleiades:*= tags: http://www.flickr.com/photos/tags/pleiades:*=/. Of these, over 4800 use pleiades:depicts= to indicate that they depict the site(s) of an ancient place; the ancient place, or what remains of it, is the subject of the photo. Over 1500 photos use pleiades:findspot= to indicate that the subject of the photo was found in the context of the ancient place. The pleiades:origin= tag is another interesting one and Flickr has almost 200 of these.

My favorite is the pleiades:atteststo= tag for photo subjects that bear the name of or otherwise attest to the existence of an ancient place. The queen of these (in my opinion) is Dan Diffendale's photo of an inscribed decree concerning the founding of the colony of Brea.

Making the Pleiades machine tags easy to use is a challenge we haven't yet overcome. It's in the nature of these tags to be specific to a relatively small number of photos. The opaqueness of our numerical identifiers further hinders reuse; when you type "pleiades:" in the tag field on Flickr (or Aperture or whatever) the resulting list of suggestions like:

pleiades:depicts=42
pleiades:depicts=43
pleiades:depicts=44
...

isn't super helpful to mere mortals (which is why things like rdfs:label exist in more robust semantic web systems, right?). Despite the limitations, I've known that we could do better at showing to users what to do and yesterday I checked off something that has been on the todo list for a while: cut-and-paste machine tags for the Pleiades place pages.

On the right side of pages (like Palmyra's, http://pleiades.stoa.org/places/668331) you'll see section labeled "Photos" that may contain a portrait of the place and links to related Flickr photos. Below this you will now see two suggested tags:

Use this tag in Flickr to mark depictions of this place's site(s):

  pleiades:depicts=668331

or this one to mark objects found here:

  pleiades:findspot=668331

If you use these, I'd appreciate a note. The approach is very low tech (select, ctrl-c, ctrl-v) and user tracking in such detail is not in our budget. I'm looking forward to finding a bump in tagged photos soon.

Let's spruce up Asia Minor!

Improving the titles and descriptions of Pleiades place resources, and linking them one to another using connections, are some of the easiest and most valuable ways that community members can help improve Pleiades content.

A Pleiades hack day is now underway in the Pleiades IRC channel. We've decided to focus on cleaning up descriptions for Pleiades place resources on the island of Sardinia. The following query gives you most of the Pleiades content for Sardinia and Corsica:

http://tinyurl.com/aotxaum

Here's our process:

1. Pick a place to improve
2. Drop the title and URL into the IRC channel, so everyone knows you're working on it
3. Check out a working copy of the place
4. In your working copy, write a better description and connect the place to the place resource for the island you're working on.
5. Submit for review
6. Ping paregorios or servilius_ahala in IRC to get it reviewed and published

We're also building an FAQ on the subject of "What Makes a Good Pleiades Description?".

An online group work session like this is a great way to start learning how to edit and improve content in Pleiades. It's also a good way to meet your fellow community members.