Hi Eric, Complex ideas that span multiple triples are often expressed through SPARQL. In other words, you store a soup of triple statements and the SPARQL query traverses the triples and presents the resulting information in a variety of formats, much in the same way you’d query a database using JOINs and present the resulting data on a single Web page.
Using your graph, this SPARQL query should return the work and the gender of the work's creator: PREFIX dc: <http://purl.org/dc/terms/> PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT ?work ?gender WHERE { ?work dc:created ?creator . ?creator foaf:gender ?gender . } If you want to explicitly state that the Declaration of Independence was written by a male, you would need a predicate that’s set up to do that, something that takes a work as its domain and has a range of a gender. It would also help to have a class for gender. That way, you could have a triple statement like this: <http://www.worldcat.org/identities/lccn-n79-89957> foaf:name “Thomas Jefferson” a :Male . and you could infer that if: <http://www.archives.gov/exhibits/charters/declaration_transcript.html> dc:creator <http://www.worldcat.org/identities/lccn-n79-89957> . The creator of the Declaration is of class :Male: <http://www.archives.gov/exhibits/charters/declaration_transcript.html> :createdByGender :Male All the best, Aaron Rubinstein On Nov 3, 2013, at 12:00 AM, Eric Lease Morgan <emor...@nd.edu> wrote: > > How can I write an RDF serialization enabling me to express the fact that the > United States Declaration Of Independence was written by Thomas Jefferson and > Thomas Jefferson was a male? (And thus asserting that the Declaration of > Independence was written by a male.) > > Suppose I have the following assertion: > > <rdf:RDF > xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"; > xmlns:dc="http://purl.org/dc/elements/1.1/"; > > > <!-- the Declaration Of Independence was authored by Thomas Jefferson --> > <rdf:Description > > rdf:about="http://www.archives.gov/exhibits/charters/declaration_transcript.html";> > > <dc:creator>http://www.worldcat.org/identities/lccn-n79-89957</dc:creator> > </rdf:Description> > > </rdf:RDF> > > Suppose I have a second assertion: > > <rdf:RDF > xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"; > xmlns:foaf="http://xmlns.com/foaf/0.1/";> > > <!-- Thomas Jefferson was a male --> > <rdf:Description > rdf:about="http://www.worldcat.org/identities/lccn-n79-89957";> > <foaf:gender>male</foaf:gender> > </rdf:Description> > > </rdf:RDF> > > Now suppose a cool Linked Data robot came along and harvested my RDF/XML. > Moreover lets assume the robot could make the logical conclusion that the > Declaration was written by a male. How might the robot express this fact in > RDF/XML? The following is my first attempt at such an expression, but the > resulting graph (attached) doesn't seem to visually express what I really > want: > > <rdf:RDF > xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#” > xmlns:foaf="http://xmlns.com/foaf/0.1/“ > xmlns:dc="http://purl.org/dc/elements/1.1/“> > > <rdf:Description > rdf:about="http://www.worldcat.org/identities/lccn-n79-89957";> > <foaf:gender>male</foaf:gender> > </rdf:Description> > > <rdf:Description > > rdf:about="http://www.archives.gov/exhibits/charters/declaration_transcript.html";> > <dc:creator>http://www.worldcat.org/identities/lccn-n79-89957</dc:creator> > </rdf:Description> > </rdf:RDF> > > Am I doing something wrong? How might you encode such the following > expression — The Declaration Of Independence was authored by Thomas > Jefferson, and Thomas Jefferson was a male. And therefore, the Declaration Of > Independence was authored by a male named Thomas Jefferson? Maybe RDF can not > express this fact because it requires two predicates in a single expression, > and this the expression would not be a triple but rather a “quadrile" — > object, predicate #1, subject/object, predicate #2, and subject? > > > — > Eric Morgan > > [cid:2A12C96F-E5C4-4C77-999C-B7FF5C2FA171@att.net] > >
