Issue
One of the major issues in RDF is how to associate metadata with a statement.
I can make a statement that "John - married_to - Joan".
What if I want to add metadata to this statement such as startdate, enddate, quality, ... ?
Jeni Tennison
Jeni Tennison describes in her
blog possible ways to deal with the issue.
Jeni describes three potential approaches:
- reification
- turning the property into a class, e.g. marriage
- using named graphs
She prefers approach 3, which opens a second discussion on how to represent best named graphs in
RDFa.
Heavily recommended, also for all kinds of useful feedback and pointers in the comments.
Ian Davis
Ian Davis of
Talis recently even elaborated on this in a 6 part series:
Representing Time in RDF.
He describes, using 3 cases, 4 different approaches:
- using conditions to model the state of being of an individual at a point in time
- using named graphs
- reification
- n-ary relations
The overview and the discussions afterwards, with very good input from
Glenn McDonald, tend to favour approach 4, where the relation is turned into a class with properties on its own.
Also worth mentioning as additional input to approach 2 (using named graphs) is a blog entry concerning
versioning of RDF graphs.
Living in the XML and RDF world
Comments
Irene Polikoff (unauthenticated)
Sep 8, 2009
Paul,
I just posted a blog entry about creating and managing metadata with the TopBraid Suite http://tinyurl.com/m6un4z.
I wanted to do this for a while, ever since I saw Ian Davis' posts, but kept procrastinating. Coming across your summary, caused me to finally do it.