Thank you Colin and David for your detailed answer. On Wed, Jun 7, 2017 at 3:28 PM, Colin Maudry <[email protected]> wrote:
> Hello Tina, > > Thank you very much for your interest for the Semantic Web. This mailling > list is specifically dedicated to a tool, Apache Jena. It's like asking > about astronomy on a list dedicated to a brand of telescopes : it's > off-topic. > > The Wikipedia article about the Semantic Web is a very good start : > https://en.wikipedia.org/wiki/Semantic_Web > > If you're fond off asking humans, I suggest you ask your question to the > following list, you will certainly get more answers : > http://lists.w3.org/Archives/Public/semantic-web/ > > Have a nice trip on the paths of the Web of data :) > > Colin > > -------- Original Message -------- > Subject: Re: Web 3 vs Web 2 > Local Time: June 7, 2017 1:25 PM > UTC Time: June 7, 2017 11:25 AM > From: [email protected] > To: [email protected] > > To see the metadata you have to consider the prefix statements that must > be made before you can use the triples in your example/ > > @prefix rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns# > > click on the hyperlink to follow it. > > Using this prefix statement adds metadata essential to understanding the > triple: > Student rdf:type Person > > rdf:type means: > rdf:type a rdf:Property ; > rdfs:isDefinedBy <http://www.w3.org/1999/02/22-rdf-syntax-ns#> ; > rdfs:label "type" ; > rdfs:comment "The subject is an instance of a class." ; > rdfs:range rdfs:Class ; > rdfs:domain rdfs:Resource . > > The object “Person” in the triple may also have metadata associated with > it. > If the prefix: > > @prefix foaf: http://xmlns.com/foaf/0.1/ > > is used the metadata associated with foaf:Person is > > <rdfs:Class rdf:about="http://xmlns.com/foaf/0.1/Person"; > rdfs:label="Person" rdfs:comment="A person." vs:term_status="stable"><rdf:type > rdf:resource="http://www.w3.org/2002/07/owl#Class"/><owl:equivalentClass > rdf:resource="http://schema.org/Person"/><owl:equivalentClass > rdf:resource="http://www.w3.org/2000/10/swap/pim/contact#Person"/><!-- > <rdfs:subClassOf><owl:Class rdf:about="http://xmlns.com/wordnet/1.6/Person > "/></rdfs:subClassOf> > --><rdfs:subClassOf><owl:Class rdf:about="http://xmlns.com/foaf/0.1/Agent > "/></rdfs:subClassOf><!-- <rdfs:subClassOf><owl:Class rdf:about=" > http://xmlns.com/wordnet/1.6/Agent"/></rdfs:subClassOf> > --><rdfs:subClassOf><owl:Class rdf:about="http://www.w3.org/ > 2003/01/geo/wgs84_pos#SpatialThing" rdfs:label="Spatial > Thing"/></rdfs:subClassOf><!-- aside: > are spatial things always spatially located? > Person includes imaginary people... discuss... > --><rdfs:isDefinedBy rdf:resource="http://xmlns.com/foaf/0.1/"/><!-- > <owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Document"/> > this was a mistake; tattoo'd people, for example. > --><owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Organization > "/><owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Project > "/></rdfs:Class> > > So you can see even a simple statement like > > Student rdf:type foaf:Person > > contains a huge amount of metadata that can be located and used by a > machine! > > On 7/6/17, 1:07 am, "tina sani" <[email protected]> wrote: > > For example, there is an rdf document about a student. > > Student rdf:type Person. Student hasName name. Student hasAdress adress > > Student study Course. > > Where is the meta data here. How machines understand this data. >
