Linked Data Principles Revisited

by Michael Hausenblas

The linked data principles formulated by Tim Berners-Lee read quite straight-forward:
1. Use URIs as names for things
2. Use HTTP URIs so that people can look up those names.
3. When someone looks up a URI, provide useful information.
4. Include links to other URIs. so that they can discover more things.

However, when it comes down to implementing them, you may start wondering how to interpret them. I guess some of them were intentionally phrased rather generic. Astonishingly, RDF is not mentioned explicitly. Though, the third principle talks about 'useful information': I think this can be interpreted to be useful for machines in the first place; we'd expect to find something at the other end of the link that is at least GRDDLable (such as microformats, RDFa, etc.). The fourth principle is also known as follow-your-nose.

One of the key ideas in linked data is to interpret the property in an RDF statement as a typed hyperlink. So, when I come accross the RDF statement
<> dc:author <http://sw-app.org/mic.xhtml#i> .
I will assume that the author of this post is indeed http://sw-app.org/mic.xhtml#i. I can learn more about this person when dereferencing this URI, i.e. do an HTTP GET to fetch its content. To learn more about URI design and usage, have a look at Cool URIs for the Semantic Web, a W3C note recently finalised.

The above mainly arose from a recent discussion with Richard Cyganiak regarding our riese system, an RDFised and interlinked version of the Eurostat data.

4 Comments

craig
2008-04-07 09:46:16
I know nothing about RDF but your example statement looks quite strange. Are the angle brackets placed correctly?
Brendan Taylor
2008-04-07 10:45:14
craig, yes they are. The RDF syntax that Michael's using there isn't based on XML; in this situation angle brackets indicate a URI.
Josh Peters
2008-04-07 12:51:01
@craig: if you know nothing of RDF, get out while you still can


j/k

Henry Story
2008-04-19 02:46:17
The syntax is N3 which you can learn very quickly. Read up on it here:
http://www.w3.org/2000/10/swap/Primer