Tuesday, December 20, 2011

Pleiades, Flickr, and the Ancient World Image Bank

Many of you are already aware that Pleiades, Flickr, and the Ancient World Image Bank have joined forces to link together online, open-access imagery and ancient geographical information. This blog post is intended to answer some lingering questions that users and potential contributors have been asking about the process.

Other Blog Posts
How to Construct a Pleiades Machine Tag

In Flickr, you add the machine tag the same way you add regular tags when editing an individual image or a set or group in the organizer. The machine tag should use the following syntax:
where "TERM" is one of the recognized terms (originally from the Concordia Thesaurus, aka the Graph of Ancient World Data, or GAWD, terms) listed below and "#####" is the numeric identifier of the Pleiades place you wish to associate with the photo.

You can get the identifier by visiting then searching for and finding the place. Copy the numeric portion of the URL of the place page and paste it into your tag.

So, for example, if I wanted to tag a photo that "depicts" ancient Athens (or a portion thereof), I'd visit Pleiades and search for Athens. I'd find this place page: So, I'd grab 579885 and construct the following machine tag for use in Flickr:
Recognized Terms in Pleiades Machine Tags

TERMS for use in Pleiades machine tags should begin with a lowercase letter. The following TERMS are recognized in Pleiades machine tags:
the photo so tagged can be said to "depict" the referenced ancient place or a significant or exemplary portion thereof
(this term is equivalent to CIDOC CRM p62 "depicts")
the photo so tagged shows an object that was first found in modern times at the referenced ancient place
(this term is particularly useful for items now in museums or elsewhere, especially those no longer at the initial place of finding)
the photo so tagged shows an object that is believed, with reasonably high certainty, to have been originally located or produced at the referenced ancient place
(this can differ from the findspot, as when an inscription or other object was moved in antiquity)
the photo so tagged shows an object that was observed in modern times at the referenced ancient place
(the implication being that the place observed is neither the modern findspot nor the presumed original location; I suspect this term will rarely need to be used to link photos with Pleiades place resources)
the photo so tagged is related in some way to the referenced ancient place, but for some unspecified reason no more specific relationship can be asserted
(this term should not be used unless none of above terms are deemed to be appropriate)
this term is DEPRECATED; it was originally used in exploring the Pleiades machine tag idea (and is highlighted in my previous blog post). Its semantics are assumed to be equivalent to "where". If at all possible, photos carrying this tag should be updated to use one of the more specific terms above.

Please note that pleiades:places=##### (i.e., with a plural) is not a recognized machine tag. Its behavior in Flickr or Pleiades is undefined. So is the behavior of any Pleiades machine tag with a misspelling or a term not included in the list above. ("finspot" seems to be a popular typo at present).

Any photo tagged with the proper Pleiades machine tag syntax and one of the terms above will be noticed by Pleiades and picked up in the summary counts and links on individual place resource pages. In order for a photo to be considered for the Pleiades Places group on Flickr (and therefore as a "portrait image" for a Pleiades place), the photo must be tagged with a pleiades:depicts tag.

How do I Add Pleiades Machine Tags Quickly?

It would be unreasonable of us to ask a prolific photographer with an extensive, well-tagged collection already on Flickr to go through an individually add appropriate machine tags by hand. Fortunately, Flickr provides a mechanism for easy batch editing of tags.
  1. Suppose that you have tagged a large number of your photos with the name of the ancient site (e.g., Halicarnassus)
  2. Visit the following link:; it will give you an alphabetical list of all your tags.
  3. Find the name of the site and click on the corresponding link. You'll see all the photos thus tagged in your photostream.
  4. Find and click on the "Change this tag" link (Really. Skip "Edit these in a batch" link for now).
  5. Insert the cursor after your existing tag string, type a space, then type or paste in the desired Pleiades machine tag (read the fine print on that page for an extended explanation of what's going on).
  6. Click the "save" button. Flickr will go off and add the new tag to all those images at once.
  7. If you'd rather be more selective about which photos you want to add a tag to, you can choose the "Edit these in a batch" link I told you to skip above, then paste the Pleiades machine tag into the tag lists associated with only those images you wish to update.
Why Can't We Just Use Geotagging That's Already in the Photos?

Some photographers have geotagged their photos, either using a GPS-enabled digital camera or some method of post-processing. I was recently asked on twitter why we're putting people to all the trouble above when we could just use the geotagging? There are several reasons:
  • Not everybody's photos are machine-tagged.
  • Many ancient sites are coincident with urban areas (or areas of natural beauty or places where someone took a picture of their dog) and so mere proximity to an ancient site can't be interpreted as indicating a given photo is relevant to a nearby Pleiades place.
  • Horizontal precision and accuracy can vary widely in geotagged photos as a function of the geotagging method used and the interests and skill of the person doing the geotagging. As a result, a photo might be geotagged at a location closer to another, unrelated pleiades place.
  • The horizontal precision and accuracy of Pleiades coordinates also varies widely given the varying sources from which it derives and the subsequent coordinate extraction methods. This makes the process of proximity correlation even more fraught.
This is not to say that we're not interested in exploring uses for geotagged photos in Flickr (or supporting a geotag-your-photo-using-Pleiades-coordinates tool), but I hope this discussion helps explain why we like the machine-tag approach for indicating relevance.

Please let me know, via comments here, if you have additional questions or suggestions. 

Tuesday, November 15, 2011

Updates to Maia and Electra Atlantis

The following blog has been added to both the Electra and Maia feed aggregators:

The following blogs have been removed:
  • Deutsches Archäologisches Institut: invalid/non-well-formed XML in feed (Maia)
  • Historical Archaeology in the Ancient Mediterranean (Brandon Olson): feed returns 404 (Maia)
  • Memiyawanzi: feed returns 404 (Maia)

Friday, November 4, 2011

It's all coming together at PELAGIOS

For years (over a decade in fact) we've been dreaming and talking about linking up ancient world resources on the web along the thematic axis of geography. Pleiades was launched in no small part in pursuit of that vision. And today comes more proof -- to which many can relate -- that hard work, collaboration, and openness bears really tasty fruit.
The Perseus geospatial data now includes annotations of ancient places with Pleiades URIs. Beginning next week, the Places widget in the Perseus interface will include links to download the Pleiades annotations in OAC compliant RDF format. These links will appear for any text with place entity markup which also has places from this dataset. We are also providing a link to search on the top five most frequently mentioned of these places in the Pelagios graph explorer.
(Check out the rest of the story, which provides a screenshot of the interface changes and a step-by-step description of how the work was done).

How did this come to be possible? Here's a very much abridged history:

  • Perseus built a path-breaking, web-based digital library of resources for the study of the ancient world; released a bunch of their code and content under open licenses; and managed the geographic aspects of the content as data
  • Pleiades built on and marshaled the efforts of the Classical Atlas Project, the Digital Atlas of Roman and Medieval Civilization, and other collaborators to publish an ever-improving geographic dataset on the web under a permissive open license
  • Leif Isaksen, on behalf of the Google Ancient Places project, took that dataset, mashed it up with another open geographical dataset (GeoNames) and published the results (Pleiades+) under a public domain declaration (more openness).
  • The PELAGIOS team took Pleiades+ and started matching it with their data. Perseus is just the latest member of that team to do so, and there are more on the way.
The resulting interface enhancements Perseus is announcing today are just the latest visible example of how the web of people benefits from the creation and exploitation of the web of data, and it's all super-charged by openness.

I'm grateful to the hard-working folks, and the array of funding agencies and host institutions, whose commitment and support are making these dreams come true.

Thursday, November 3, 2011

Closing in on a Pleiades hack day date

Thanks to all who have registered their interest in, and availability for, the proposed Pleiades hack day to work on titles and descriptions for "well-known" places. By the close of business today (Thursday, 3 November 2011, US Eastern time), I'll announce the day for the hack day based on the majority availability as indicated in the scheduling poll.

If you want to have an influence over the date selection, please post a comment here or email me and I'll send you a link to the scheduling poll.

Tuesday, November 1, 2011

Changes to Maia and Electra

The following changes have been made to the Electra and Maia feed aggregators:

  • Added Johan Ålfeldt's Regnum Francorum Online
  • Removed Greek and Roman Studies: IWU Student Posts from Abroad (feed generates 404, and so does the blog itself)
  • Removed duplicate Compitum subscriptions
  • Removed David Beard's Archaeology in Europe because the feed contains invalid tags

Friday, October 28, 2011

Pleiades Hack Day

I'm thinking it's time. Time we designated a particular day to give over to ganging up on Pleiades content and making it better. Looking at the low-hanging-and-annoying-fruit list, the first thing that comes to mind is improving our titles and descriptions to facilitate discovery and disambiguation. I've laid out what I see as the landscape in a document on the Pleiades site: Improving Titles and Descriptions for Prominent Places.

So what remains is to see who would be willing to devote at least a couple of hours (if not a whole day) to this enterprise and to fix a day for it. You don't need to be an expert to help with this job. Anyone interested at all in ancient geography who has basic web skills and can get on the internet at the scheduled time should be able to make a substantive contribution, whether they are a student, a scholar or an interested "layperson".

If you're interested, leave a comment on my blog and I'll send you a link to a doodle poll to do the scheduling.

Tuesday, October 25, 2011

Meetup: The Future of the Ancient World Image Bank

So, my brain has mashed up its happiness at the success of last week's Pleiades community meetup with the hanging conversations that started in response to my blog post on Pleiades machine tags in Flickr. Nate Nagy (AWIB Managing Editor) and I had a good conversation a couple of weeks ago about the future of AWIB, one that would be more open and collaborative than the current model.

I'd like to light a fire under (and refine) those ideas. I'm starting a Doodle poll to find a time for a "future of AWIB" meetup, to be held via Google+. I'll send invites to all of our contacts on Flickr and others who have expressed interest. Please post a comment here if you'd like to be part of the event.

Thursday, October 20, 2011

Unexpected End to a Halloween Tradition

There's a thread going about this on Facebook, but since that's a walled garden I'm going to repeat my initial post here for the consideration of a wider audience (assuming there is an audience):

So the answer to the question "When are we going to hear about the Randolph School Halloween Carnival this year" seems to be: "there's not going to be one; it's been rebranded as the 'first-ever Raider Ruckus'". Color me sad and frustrated. An extended pep rally is fine and good, but the Halloween Carnival was a great tradition and gave our kids a fantastic venue for the holiday. The question now is: "what rationale, and driven by whom, brought about this change?"

And, no, I'm guessing they're not aware that the Urban Dictionary glosses a "raider ruckus" as a "drug dealer" (citing a lyric from Method Man's What the Blood Clot).

Wednesday, October 19, 2011

Taygete Atlantis (Dig Blogs) Returns to Service

I've just returned the Taygete Atlantis Archaeological Dig Blog Aggregator to service, with the following changes:

You can view the full subscription list on the Taygete Atlantis page, or download it in OPML form to install in your own feed reader. 

Please drop me a line if you know of excavation blogs that should be added.

Monday, October 17, 2011

Recently Added to Maia Atlantis

The following blogs have recently been added to the Maia Atlantis Feed Aggregator:

Recently Added to Electra Atlantis

The following blogs have recently been added to the Electra Atlantis feed aggregator:

Maia Atlantis Returns to Service, With Changes

The Maia Atlantis feed aggregator has just been put back into service. The following blogs are no longer indexed:

  • Arkeologi Lampung: feed not well-formed
  • Fernando Lillo Redonet (Latín y Cultura Clásica en el siglo XXI): feed hangs on request
  • Nick Nicholas (Ἡλληνιστεύκοντος): feed contains invalid unicode character
  • CHS Fellowships Research Blog: feed returns 404 "not found"
  • Antiquity Lives: feed returns 404 "not found"
  • Épave sous-marine : Arles-Rhône 3: feed not well-formed

Pleiades Google+ Hangout this Wednesday

Details here.

Sunday, October 16, 2011

Electra Atlantis is Back

Thanks to Sean Gillies, the Electra Atlantis feed aggregator has been up and running again for a couple of days. I'm still trouble-shooting the other aggregators to find the culprit. More news here as the others are brought back online.

Tuesday, October 11, 2011

Linked Open Data: Short Version

So, here's what I think I said -- in a caffeine and government-issued-muffin-induced frenzy -- a couple of weeks ago at the NEH Digital Humanities Project Directors' Meeting:

  • Linked: your data is my metadata / my data is your metadata
  • Open: your data is my data / my data is your data
  • Data: stop using computers to produce information resources that require manual human processing / start using computers to produce information resources that other computers can use automagically

Monday, October 3, 2011

Planet Atlantides Feed Aggregators Temporarily Suspended

Due to a technical problem, I've had to suspend updates to all of the feed aggregators at I'll troubleshoot the problem and get them back up and running after I return from vacation on the 10th of October. I'm sorry for any inconvenience this may cause in the interim.

If you would like to get the latest information from all the blogs associated with any of these aggregators, please grab the OPML file for the aggregator you're interested in (it contains a list of all the feeds from which the aggregator pulls) and import it into a compatible feed reader of your choice.

Friday, September 30, 2011

A Better Location for Forum Gallorum?

René Voorburg has raised concerns over the Pleiades location for Forum Gallorum (, given relevant evidence from the Antonine Itineraries. You can see his comment, and my initial response, at

I'd be grateful if some interested party, who has local access to TIR Caesaraugusta*, can check pages 117-118 to see on what grounds it locates Forum Gallorum at Cerro de San Mitiel (Ayerbe) and whether it addresses the anomalous distance measures René noticed. Neither René nor I have immediate access to the volume.

Please provide your response by appending a comment to the above discussion thread. All you need to submit comments to Pleiades is an OpenID. Many thanks!

* TIR Caesaraugusta = Tabula Imperii Romani K-30, Madrid: Caesaraugusta, Clunia (Madrid: 1993).

Wednesday, September 28, 2011

NEH Project Directors' Meeting

John Muccigrosso and I had a good time at the NEH Project Directors' Meeting in Washington yesterday (#SUG2011 was the twitter hash tag). Here are the slides that Sebastian Heath whipped up for our 2-minute lightning talk about the forthcoming Linked Ancient World Data Institutes (spring 2012 at ISAW; spring 2013 at Drew U.). I blogged my notes on Linked Open Data yesterday.

Tuesday, September 27, 2011

Linked. Open. Data.

As we get spun up for our Linked Ancient World Data Institute (LAWDI) and move toward more interlinkedness between Pleiades,, the Ancient World Image Bank and other resources, I've been refreshing my thinking on Linked Open Data (LOD). Among the fodder for this thinking is Tim Berners-Lee's "Linked Data - Design Issues." Today's Digital Humanities Project Directors meeting at NEH has John Muccigrosso and myself channeling Sebastian Heath in a lightning talk, so I thought I'd better get my thoughts in order. It falls to me to briefly define linked open data so John can talk about the institute.

Berners-Lee's piece presents two lists of criteria/considerations/characteristics of linked open data in a way that doesn't entirely reconcile the two. They're overlapping and complementary, but they clearly represent two different stages in the promotion of the idea. I think those lists can be remixed into a single list with three clear rubrics that are easy to remember.

  • Put your content on the web (not under or inside or over it)
  • Assign (stable) Uniform Resource Identifiers (URIs) as names to discrete entities and ideas in your content
  • Use HTTP URIs to enable lookup of the names and hide implementation detail
  • Provide useful information about named entities on lookup
  • Link to other URIs to facilitate discovery
    • Typed links define relationships between named entities both within and beyond your content
    • Typed links facilitate assertion and inference
  • Bottom line: my data is your metadata
  • Publish under open licenses (e.g., Creative Commons Attribution, GNU Public License)
  • Publish in non-proprietary formats
  • Publish machine-readable content
  • Facilitate discovery via browsing and crawling (i.e., don't require searching/guessing)
  • Bottom line: my data is your data
  • Publish structured data, not just documents
  • Treat both content and links as data
  • Express internal and external links in well-defined forms like RDF
  • Bottom line: our machines can help

Monday, September 26, 2011

Describing Pleiades

Matt Knutzen recently sent me a draft description of the Pleiades project and asked for my thoughts on it. Here's what resulted:
The Pleiades Project ( is a consortially developed, open-source, web-based platform for using, creating, improving and sharing historical geographic information about the ancient world. It employs a unique data model that adapts best-practice and standards in GIS and spatial computing to deal with the unique challenges of sparse, damaged and contested information about ancient places, spaces and names. The project began by adapting and publishing all the data gathered for the Barrington Atlas of the Greek and Roman World, but is now working with partners to expand temporally and spatially into Late Antiquity, the Byzantine Empire, the ancient Near East, Egypt and beyond.

Saturday, September 10, 2011

Feeds of Flickr Photos Depicting Pleiades Places

Some months ago, ISAW started adding Pleiades machine tags to the Ancient World Image Bank (AWIB) photos we've been uploading to Flickr. This post will explain what that means, how it might be useful to you and how you can add Pleiades machine tags to your own photos so we can find out about them.

Updated: 8:45pm EDT, 10 September 2011 (changes highlighted in orange).
Updated: 10:43am EST, 20 December 2011 (some of what's here is now superseded by recent developments; see further this new post: Pleiades, Flickr, and the Ancient World Image Bank)

Pleiades Machine Tags

Pleiades is a collaborative, open-access digital gazetteer for the ancient world. AWIB is an open-access publication that uses the Flickr photo-sharing site to publish free, reusable photos of ancient sites and artifacts. Machine tags are an extension to Flickr's basic tag-this-photo functionality that "use a special syntax to define extra information about a tag" (Aaron Straup Cope, "Ladies and Gentlemen: Machine Tags," 24 January 2007).

A Pleiades machine tag looks like this:
where 795868 is the stable identifier portion of a Pleiades Uniform Resource Identifier (URI).  In this example, the URI corresponding to the machine tag above is:
Note what's in common between the machine tag and the URI (highlighted in yellow).

What Pleiades Machine Tags Are Good For

The Flickr API makes it possible to request lists of machine-tagged photos in the RSS webfeed format. So, to get a list of all photos in Flickr that are tagged with the example machine tag above, pop this into your feed reader:
The same results can be viewed in HTML in a browser by resolving the following:
To get a list of all photos in Flickr that are tagged with any Pleiades machine tag, try this (the API syntax supports wildcards!):
The same results, viewed in HTML on the Flickr site:
Feeds like these aren't just for feed readers anymore. You can add user-interface widgets to your blog or website to summarize the latest content for your readers (check out the right-hand column in this blog). You can hook up services like Networked Blogs or Twitterfeed to pass on the latest changes to your Facebook friends or Twitter followers. If you've got a web-facing numismatic database that you've already linked up with Pleiades for the mint locations, you could write custom code to pull a corresponding picture of the ancient site into your web interface (say, alongside the map you've already got).

Add Pleiades Machine Tags to Your Own Photos on Flickr

Many of you have been taking amazing photos of ancient sites and artifacts for years. Many of you have posted some of them to Flickr and shared them with great groups like Chiron, Visibile Parlare - Greek Inscriptions and Visibile Parlare - Latin Inscriptions. If you'd like these photos to appear in queries and feeds (like those described above), right alongside the photos that we're publishing via AWIB, all you have to do is add the appropriate Pleiades machine tags in Flickr. Just look up your site on Pleiades, copy the numeric ID from the URI in your browser's location bar, append it to the string "pleiades:place=" and tag your Flickr photos with it. In this way, you can help us improve findability of good photos of ancient sites and the artifacts found there for everyone on the web. Who knows ... maybe enough people will join us in this effort that we can someday get the Flickr development team to give Pleiades machine tags some extra love.

Kudos to:

Friday, May 13, 2011

Post-Tornado: Helping Alabama School Libraries

I learned today from the president of the Alabama School Library Association that at least 8 schools in the state sustained major damage or were totally destroyed in the tornado outbreak on 27 April 2011. There are many other schools that have sustained roof or other damage, and still several others that the ASLA has not yet been able to contact. The affected school libraries have lost many or all of their collections; they will need to be replaced along with the rest of the school infrastructure. In the meantime, many of the school librarians and other administrators are serving as focal points for the distribution of donated books to children who have lost homes and possessions.

I'm going to do what I can to help, and I'd be grateful if friends and colleagues would consider helping as well.

Officers and Board Members of the ASLA are collecting new and gently used books for distribution to schools and local relief efforts. If you would like to contribute, please contact them via their website.

There's also vendor-run effort to collect money for new books for library collections that will be chosen by the librarians themselves. The vendors are matching contributions. You can contribute online (via Paypal) at Alabama School Disaster Relief.

Friday, April 8, 2011

Numishare: Ethan Gruber's code and blog

I've just added the Numishare blog to the Electra Atlantis feed aggregator. Ethan Gruber uses it to disseminate news about Numishare, an "open source project hosted by Google Code for the creation, management, and dissemination of numismatic data online."

Thursday, April 7, 2011

Wednesday, April 6, 2011

Added to Maia Atlantis: Byzantine News

I've just added the following blog to the Maia Atlantis feed aggregator:

Changes to Electra and Maia Atlantis

This morning I've added the following blogs to the Electra Atlantis feed aggregator:
Thanks to Adam Brin at Digital Antiquity for alerting me to their existence.

I have updated feed addresses in Electra for the following blogs, which have changed recently:
I have also removed the following blogs for the reasons indicated:
  • The feed URL for the Center for Digital Research in the Humanities (Univ. of Nebraska-Lincoln) is returning an error 500
  • Sheila Brennan's Relaxing on the Trail has had its permissions reset so that it is no longer accessible.
  • Notis Toufexis' blog seems to have disappeared.
I have added the following blogs to the Maia Atlantis feed aggregator:

Friday, February 25, 2011

Zeugma at Pleiades and ISAW

In honor of Kutal Gorkay's upcoming talk at ISAW (Recent Archaeological Research in Zeugma: March 21, 2011), I've taken the opportunity to update the Zeugma resource at Pleiades. It now has:
  • a precise location (taken from the visible remains of the theater)
  • Greek orthography for the name Zeugma (Ζεύγμα) -- I couldn't quickly find a verifiable ancient reference for the other name we inherited from the Barrington: Seleukeia pros to Euphrate
  • an updated description and place type (settlement)
  • a modestly expanded "details" section in which I link to Zeugma resources elsewhere (including the official excavation website, Wikipedia, and some digital publications by David Walker at the University of Western Australia)
I hope you'll check out both the lecture notice and the Pleiades resource. I'd of course be grateful for comments, corrections and additions to the latter. 

And if you think you could do something like this for another Pleiades place resource, by all means, please join up and give it a try. You'll find how-to instructions in my Valentine's Day Pleiades Post. If you've got Irish interests or ancestry, why not pick an ancient site in Ireland to spruce up in celebration of St. Patrick's Day!

Zeugma on Pleiades:
Ancient sites in Ireland link courtesy of the spatial search functions Sean Gillies recently added to Pleiades.

Friday, January 21, 2011

Adopt a place for Valentine's day

Pleiades places are looking for love and this year you can give it to them (it never hurts to get ready for Valentine's Day early). It will only take a few minutes of your time.

Here are some examples of things you could do (many of them quickly) to enhance the content in Pleiades:
Here are some ways you could use links to Pleiades to enrich content elsewhere on the web
Feel free to suggest other ways (with links to examples, where appropriate) in the comments.

How to get started

Are you a registered Pleiades user? If not, please visit the Pleiades Community page and follow the instructions there.

If you are a registered Pleiades user and you want to make a modification to a place resource (improved on 24 January):
  • log in
  • use the search box to find the place resource you're interested in changing
  • select "actions" ... "check out" (this will create a working copy for you)
  • select the "edit" tab
  • make and save your changes as many times as you like (you're working on a private copy of the original that only you can see)
  • once you're happy with the results, select "state: drafting" and change it to "submit for review"
  • the editors will review your suggested changes and be in touch via email if they have any questions ... otherwise they'll add your name to the "creator" or "contributor" field (as appropriate) and publish the changes so everyone can see them
Get stuck? 

Ask a question on the pleiades-community list, to which all Pleiades users are automatically subscribed.

Your Pleiades place is waiting for you!

Wednesday, January 5, 2011

Changes to Maia Atlantis

I've temporarily removed FastiOnline from the Maia Atlantis feed aggregator because its entries keep getting redated to the current day, causing them to remain at the top of the aggregation list.