- From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
- Date: Thu, 26 Apr 2012 17:30:09 +0200
- To: Richard Cyganiak <richard@cyganiak.de>
- CC: RDF WG <public-rdf-wg@w3.org>
Hi, (This email is mostly for Richard's attention) Putting aside the discussion on dataset semantics, I have a few comments on the way the dataset proposal is described in terms of syntax: "The RDF data model expresses information as graphs consisting of triples with subject, predicate and object." The word "graph", in the RDF specifications, should never appear alone like this. It is well known that a graph is a pair (V,E) where V is a set of vertices and E is a set of edges. This is not what RDF Graphs are. RDF Graphs are not graphs, in any of the accepted mathematical definition of the term. We already agreed that the word "graph" alone is ambiguous and we resolved to use the phrase "RDF Graph" whenever we talk about sets of triples. SUGGESTION: "The RDF data model expresses information as RDF Graphs consisting of a set of triples with subject, predicate and object." ----- "Often, one wants to hold multiple RDF graphs and record information about each graph, allowing an application to work with datasets that involve information from more than one graph." SUGGESTION: "... each RDF Graph, ... than one RDF Graph." To sound less redundent, "hold multiple RDF graphs and record information about each one, ..." ----- "An RDF Dataset represents a collection of graphs. An RDF Dataset comprises one graph, the default graph, which does not have a name, and zero or more named graphs, where each named graph is identified by an IRI." Maybe say "distinguished RDF Graph": SUGGESTION: "An RDF Dataset comprises one distinguished RDF Graph, the /default graph/, which does not have a name, ..." Moreover, the word "identified" may be missinterpreted. SUGGESTION: "..., where each named graph associates an IRI with an RDF Graph." ----- "An RDF Dataset may contain zero named graphs; an RDF Dataset always contains one default graph." SUGGESTION: add "The default graph MAY be empty." ----- Maybe a definition for "named graph" could be given before the formal definition of RDF Dataset: SUGGESTION: "A /named graph/ is a pair (n,g) where n is an IRI called the /graph name/ and g is an RDF Graph." ----- "Formally, an RDF dataset is a set: { G, (<u1>, G1), (<u2>, G2), . . . (<un>, Gn) } where G and each Gi are graphs, and each <ui> is an IRI. Each <ui> is distinct." "... are RDF Graphs, ..." ---- "G is called the default graph. The pairs (<ui>, Gi) are called named graphs." If "named graph" is defined before, it could look like this: SUGGESTION: "G is called the default graph. The pairs (<ui>, Gi) are named graphs." -- Antoine Zimmermann ISCOD / LSTI - Institut Henri Fayol École Nationale Supérieure des Mines de Saint-Étienne 158 cours Fauriel 42023 Saint-Étienne Cedex 2 France Tél:+33(0)4 77 42 83 36 Fax:+33(0)4 77 42 66 66 http://zimmer.aprilfoolsreview.com/
Received on Thursday, 26 April 2012 15:31:26 UTC