It's a mistake (although understandable... better tutorials and demos are needed) to assume that RDF and SemWeb ignore this problem space.
There's an online SPARQL demo at http://xmlarmyknife.org/api/rdf/sparql/query and another at http://librdf.org/query to get a feel for how some of this stuff works. There are also tools like SquirrelRDF and D2RQ that wrap existing (SQL, LDAP,...) datasources and make them look like SPARQL too, so your apps can be couched in terms of globally-used schemas rather than per-datasource schemas. It's also worth keeping an eye on what Oracle have been up to... http://www.oracle.com/technology/tech/semantic_tec hnologies/index.html... no SPARQL yet but some serious RDF support.
"Susan saw the dog in the window. She pressed her nose against it. She wanted to buy it."
The SW project exists *because* machines are too dumb to read English. Or Chinese. And will probably stay that way for the forseeable future.
So W3C's RDF is positioned half-way between the world of dumb computers and smart people. It structures data in terms of classes and properties, and allows different groups to define sets of class and property names that can be freely mixed together without the need for heavyweight standardisation. And it gives us an SQL-ish querying framework, SPARQL, for asking questions of this data, and getting back tables of results. Despite the myths, RDF doesn't oblige people to put metadata "inside ever Web page". It just defines a common data model that information from various sources and formats can be mapped to, so that what they say can be processed with less regard for fiddly detail of file formats and encodings. And RDF certainly doesn't require that you believe everything you read: the SPARQL spec, unlike SQL, provides built-in machinery for querying properties of the data source, inline in your query, so you can filter the data down to the bits you decide to trust in some specific app.
Re:Where're the Semantics?
on
Practical RDF
·
· Score: 2, Insightful
The RDF design addresses the concerns you raise, by virtue of RDF's focus on data merging. You can't take two arbitrary XML documents and (without domain knowledge) reliably merge the information they encode. You can with RDF; just merge the sets of triples that constitute the two RDF graphs. This has knock-on effects in the real world: the granularity of "mixing and matching" between independent vocabularies is much finer. Instead of picking whole document formats, you can use just some parts of another's RDF vocabulary. This gets us away from a situation where you have to decide to use, or not use, an entire XML vocabulary.
For example, FOAF documents often contain bits of markup designed in other fora, alongside terms from the core FOAF vocabulary. Markup that describes places (lat/long/alt etc)., documents (Dublin Core), syndication (RSS), 1000s of noun terms (Wordnet), and various others (blood type, food preferences, biographical details).
RDF makes it cheaper to put together this sort of composite information, since the groups (formal and informal) who came up with these vocabularies didn't need to sit around a table together and agree a single common DTD or XML schema. They each did what they do best, and RDF glues it all together.
Re:RDF will take off when they use it for porn
on
Practical RDF
·
· Score: 1
re RDF for porn... http://rdfweb.org/2002/svgsemantics/picsn g-demo.ht ml good for finding it, good for filtering it...
also re rdf/foaf addons for slash, there are some rough notes in the FOAF wiki, see http://rdfweb.org/topic/SlashFoaf
Re:Scary page
on
Practical RDF
·
· Score: 2, Interesting
Yeah, it was staring into their cold dead eyes that had me generate this one for the FOAFCorp, http://www.foaf-project.org/images/foaf lets.corp.p ng
(foafcorp: http://rdfweb.org/foafcorp/intro.html -- reworking of theyrule.net data in rdf and svg)
Another non-Netscape Mozilla development... this is looking into the use of W3C RDF for logic/inference applications (eg. client-side decision support tools). See the Mozilla Enabling Inference pages for details, and Geoff Chappell's Mozillation announcement on the RDF Interest Group.
DARPA's RDF-related Agent language might also be of interest to/. conspiracy theorists...;-)
Slashdot Mirror
Oops, should've previewed my post. Angle brackets in my query examples. See http://www.w3.org/TR/rdf-sparql-query/#specDataset for the real thing plus the corresponding resultsets.
Re the "very very very important question of where it comes from" and RDF, ...
t
...take a look at the example query there:
... better tutorials and demos are needed) to assume that RDF and SemWeb ignore this problem space.
...) datasources and make them look like SPARQL too, so your apps can be couched in terms of globally-used schemas rather than per-datasource schemas. It's also worth keeping an eye on what Oracle have been up to ... http://www.oracle.com/technology/tech/semantic_tec hnologies/index.html ... no SPARQL yet but some serious RDF support.
See the RDF query spec, SPARQL, specifically the "FROM" clause in the query language.
http://www.w3.org/TR/rdf-sparql-query/#specDatase
Section "8.3.1 Accessing Graph Names"
PREFIX foaf:
SELECT ?src ?bobNick
FROM NAMED
FROM NAMED
WHERE
{
GRAPH ?src
{ ?x foaf:mbox .
?x foaf:nick ?bobNick
}
}
The spec gives the resultset table, which basically says that according to http://example.org/foaf/aliceFoaf the nickname is "Bobby", and according to http://example.org/foaf/bobFoaf the nickname is "Robert".
It's a mistake (although understandable
There's an online SPARQL demo at http://xmlarmyknife.org/api/rdf/sparql/query and another at http://librdf.org/query to get a feel for how some of this stuff works. There are also tools like SquirrelRDF and D2RQ that wrap existing (SQL, LDAP,
"Susan saw the dog in the window. She pressed her nose against it. She wanted to buy it."
The SW project exists *because* machines are too dumb to read English. Or Chinese. And will probably stay that way for the forseeable future.
So W3C's RDF is positioned half-way between the world of dumb computers and smart people. It structures data in terms of classes and properties, and allows different groups to define sets of class and property names that can be freely mixed together without the need for heavyweight standardisation. And it gives us an SQL-ish querying framework, SPARQL, for asking questions of this data, and getting back tables of results. Despite the myths, RDF doesn't oblige people to put metadata "inside ever Web page". It just defines a common data model that information from various sources and formats can be mapped to, so that what they say can be processed with less regard for fiddly detail of file formats and encodings. And RDF certainly doesn't require that you believe everything you read: the SPARQL spec, unlike SQL, provides built-in machinery for querying properties of the data source, inline in your query, so you can filter the data down to the bits you decide to trust in some specific app.
The RDF design addresses the concerns you raise, by virtue of RDF's focus on data merging. You can't take two arbitrary XML documents and (without domain knowledge) reliably merge the information they encode. You can with RDF; just merge the sets of triples that constitute the two RDF graphs. This has knock-on effects in the real world: the granularity of "mixing and matching" between independent vocabularies is much finer. Instead of picking whole document formats, you can use just some parts of another's RDF vocabulary. This gets us away from a situation where you have to decide to use, or not use, an entire XML vocabulary.
For example, FOAF documents often contain bits of markup designed in other fora, alongside terms from the core FOAF vocabulary. Markup that describes places (lat/long/alt etc)., documents (Dublin Core), syndication (RSS), 1000s of noun terms (Wordnet), and various others (blood type, food preferences, biographical details).
RDF makes it cheaper to put together this sort of composite information, since the groups (formal and informal) who came up with these vocabularies didn't need to sit around a table together and agree a single common DTD or XML schema. They each did what they do best, and RDF glues it all together.
re RDF for porn...n g-demo.ht ml
http://rdfweb.org/2002/svgsemantics/pics
good for finding it, good for filtering it...
also re rdf/foaf addons for slash, there are some rough notes in the FOAF wiki, see http://rdfweb.org/topic/SlashFoaf
Yeah, it was staring into their cold dead eyes that had me generate this one for the FOAFCorp,f lets.corp.p ng
http://www.foaf-project.org/images/foa
(foafcorp: http://rdfweb.org/foafcorp/intro.html -- reworking of theyrule.net data in rdf and svg)
Another non-Netscape Mozilla development... this is looking into the use of W3C RDF for logic/inference applications (eg. client-side decision support tools). See the Mozilla Enabling Inference pages for details, and Geoff Chappell's Mozillation announcement on the RDF Interest Group.
DARPA's RDF-related Agent language might also be of interest to /. conspiracy theorists... ;-)
-- danbri