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

• A general notice of the development on the ISAW News Blog (by me)
• An extended discussion of the effects, from the Pleiades perspective (by Sean Gillies)
• An extended discussion with developers' how-to on the Flickr Code Blog (by Sean Gillies), mirrored on Sean's blog
• The blog post here at Horothesia that started it all (by me)

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:

pleiades:TERM=#####

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 pleiades.stoa.org 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: http://pleiades.stoa.org/places/579885/. So, I'd grab 579885 and construct the following machine tag for use in Flickr:

pleiades:depicts=579885

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:

depicts

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")

findspot

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)

origin

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)

observedAt

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)

where

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)

place

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: http://www.flickr.com/photos/me/alltags/; 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. 

Updates to Maia and Electra Atlantis

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

• Classics at Furman (Christopher Blackwell)

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)

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.

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.

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

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.

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.