Trying to show how resource description on sites such as Flickr relates to metadata…
Some people have looked at the metadata requirements for the UK OER programme and taken them as a prescription for which LOM or Dublin Core elements they should use. After all that’s what metadata is, isn’t it? But UK OER projects are also encouraged to use Web2.0 or social sharing platforms (Flickr, YouTube, SlideShare etc.) to make their resources available, and these sites don’t know anything about metadata, do they?
Well, in my previous post I tried to distinguish between resource description and metadata, where resource description is pretty much any information about anything, and metadata is the structured information about a resource (acknowledging that the distinction is not always made by everyone). I think that some of the “metadata” requirements given for OER in various discussions are actually better seen at first as resource description requirements.
The second problem with seeing the UK OER metadata requirements as a prescriptions for which elements to use is that, to me at least, it misses the point of what metadata does best. I think that the best view of metadata is that it shows the relationship between resources. “Resources” here means anything — information resources like the OERs, people, places, things, organizations, abstract concepts — so long as the thing can be identified. What metadata does is express or assert a relationship such as “this OER was created by this person”.
So looking at an image’s “canonical” page on Flickr, we see a resource description which has a link to the photo stream of the person who uploaded it (me) and from there there is a link to my profile page on Flickr. That’s done with metadata, but how do we get at it?
Well, in the HTML for the image page the link is rendered as
title="Link to phil barker's photostream"
the rel=”dc:creator cc:attributionURL” tell a computer what the relationship between this page and the URL is, i.e. that the URL identifies the creator of the page and should be used for attribution. That’s not great because I’m not my photostream, in fact my photostream doesn’t even describe me.
Things are better on the photostream page though, it has in its HTML
title="Flickr: phil barker's Photostream RSS feed"
which points any application that knows how to read HTML and RSS to the RSS feed for my photostream, where we see in the entry for that picture the following:
<author flickr:profile="http://www.flickr.com/people/philbarker/">email@example.com (phil barker)</author>
As well as the description of me (my name and not-my-email-address) there is the link to my profile page. Looking at the HTML for that profile page, not only does it generate a human readable rendering in a browser, but it includes the following
<span class="nickname">phil barker</span>
<span class="fn n">
That is a computer readable hCard microformat version of my contact information (coincidentally it’s the same underlying schema for person-data that is used in the LOM)
So there’s your Author metadata on Flickr. And I’ll note that all this happened without me ever thinking that I was “cataloguing”!
To generalise and idealise slightly, the resource pages (the canonical page for the image, the photostream page, my profile page) have embedded in them one or more of the following
- links which describe the relationship of the resources described on those pages to each other in a computer-readable manner
- links to alternative descriptions in machine readable metadata, e.g. an RSS or ATOM XML file for the resource described on the page
- embedded computer readable metadata, e.g. vCard person-data embedded in the hCard microformat.
See also Adam’s post Objects in this Mirror are Closer than they Appear: Linked Data and the Web of Concepts.