Tagging relationships

pezman

It would be nice to be able to tag the relationship between items, e.g. something like:

<dc:relation RDF:resource="#item:2613">
<dc:subject>artistic influence</dc:subject>
</dc:relation>

This would allow an ad-hoc semantic net to be layered on Zotero's inherent research semantics.

Cooler still would be an ability to use Zotero nodes to impose rich descriptions of "related" entries such that you can layer a semantic hyper-net on Zotero's built-in semantics (i.e. relationships become rich, reusable nodes rather than simple keywords). The syntax might look like:

<dc:relation RDF:resource="#item:2613">
<dc:subject RDF:resource="#item:6955"/>
</dc:relation>

I'm not a RDF expert by any stretch, and this might be complete RDF gibberish, but the intent here would be to express that there is a relationship to #item:2613 and that this relationship is described by #item:6955 (which may presumably have subordinate relation terms).

bdarcus

Yeah, your description and examples are a little funky/unclear.

The key to RDF is the graph (of relationships), and the nodes in that graph are identified by URIs. So anything where it might be valuable to merge data across, you want to define as an identified resource.

So for your "artistic influence" tag, you could give it a URI:

<skos:Concept rdf:about="http://zotero.org/concepts/artistic_influence">
<skos:label xml:lang="en">artistic influence</skos:label>
</skos:Concept>

Then, anytime anyone uses that URI, like ...

<dc:subject rdf:resource="http://zotero.org/concepts/artistic_influence"/>

... you know they're referring to the same thing. The URI becomes like a global database key.

pezman

I was thinking more along the lines of modeling the kinds of relationships described in this paper:
http://www.dcc.uchile.cl/~cgutierr/ftp/bipartite.pdf.

I did run across RGML, but it seems oriented towards using hypergraphs in a limited way (appears to focus mostly on capturing relationships with arity > 2).

At any rate, I think that my attempt to "illustrate" using pidgin RDF distracted from my main point -- it would be cool to be able to label "related" entries and it would be cooler still to be able to label them with item nodes rather than words. As it currently stands, it only seems possible to state that two items are related.

The whole idea may be outside Zotero's intended domain of application, and there are a lot of potential complications in implementation, but googling "description logic semantic hypergraphs" turns up a ton of stuff that mentions RDF, semantic web etc., so it might be a nice feature at some point ...

bdarcus

The discussion of hypergraphs and such is outside my frame of reference (I'm much more comfortable thinking in terms of RDF graphs; triples and URIs), but the point that simply saying two items are related (which is the only thing possible now in Zotero) is a limitation is a good one. There's been discussion on this forum about broadening the kinds of relations it can support.

RDF itself is all about relations, so has few restrictions. For example, the dcterms:isPartOf property is a sub-property of dc:relation, so in using the former you are in essence doing what I think you are asking for.