Tags per Commons Photo

Posted by striatic in Statistics

Indicommons Chief of Development David Wilkinson recently investigated the distribution of tags across the Flickr Commons, creating the following graph from the data he accumulated.


Since almost every institution adds its institution name as a tag to every photo it uploads, every Commons photo possesses at least one tag. This accounts for the spike on the far left. The second spike, at three tags, is probably due to institutions like the Library of Congress adding a couple of institution specific “machine tags” to every photo they upload.

With this knowledge we can assume that many of the photos in the Commons with 3 or fewer tags have not been tagged by a Flickr member. Perhaps 2,500 or more of the 12,000 or so photos in Commons have not received any “member” tags. At around 20%, these untagged photos represent a sizable percentage of the Commons collection.

While the relatively large number of untagged photos in the collection is unfortunate, the graph also indicates that when Flickr members turn their attention to tagging photos, they add a significant number of tags. The graph’s curve crests at 9 or 10 tags, more than enough to thoroughly describe the visual contents of each image. Many photos receive even more tags than that. Indeed, David’s analysis was spurred by Shelley Mannion’s recent remark on Twitter that the Library of Congress had reached Flickr’s 75-tag-per-photo limit on certain uploads.

The following 15 photos from the Library of Commons collection possess 70 or more tags:

Library of Congress

Spreading this wealth of metadata seems to depend on connecting the untagged Commons photos with tag-happy Flickr members, who are clearly very industrious, in an effort to prevent photos from falling through the cracks and remaining entirely untagged.

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4 Responses to “Tags per Commons Photo”

  1. Stephanie Fysh Says:

    Patrick Peccatte has compiled some numbers on tagging (including machine tagging) and commenting, broken out by institution, and published them here: http://blog.tuquoque.com/post/2009/02/08/The-Commons-sur-Flickr-quelques-chiffres

  2. George Says:

    David! You super-duper Chief of Development, you! What else have you got??!

  3. dopiaza Says:

    You’ll just have to wait and see… :-)

  4. lifeasdaddy Says:

    Patrick Peccatte has also compiled a list, per institution, of photographs which have no Flickr user generated comments, tags or notes.


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