Berners-Lee
ISWC, November 2005

Putting the Web back in Semantic Web

Random reflections on ISWC,
and busting some myths
and a few challenges

ISWC Wrapup - RuleML kickoff

http://www.w3.org/2005/Talks/1110-iswc-tbl/

Tim Berners-Lee

CSAIL, MIT


Levels of semantics in publication

  1. Scraped unstructured text and multimedia content
  2. Scraped semi-structured XML
  3. Scraped XML
  4. XML (may be XHTML) with GRDDL (OK)
  5. Published RDF (Yes!)
With data, generate HTML from the RDF, not the other way around.

Sem Web architecture 101


Define symbols:
Chis Welty/IBM: "In the Semantic Web, it is not the Semantic which is new, it is the Web which is new".

Web architecture 101



Example


http://www.w3.org/People/Berners-Lee/card#i

http://www.w3.org/People/Berners-Lee/card  (in N3, summarized):

@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix : <#>.

:i a foaf:Person;
 foaf:family_name "Berners-Lee";
 foaf:givenname "Timothy";
 foaf:homepage <http://www.w3.org/People/Berners-Lee>;
 foaf:mbox <mailto:timbl@w3.org>.

Counterexample


FOAF: Follow the rdfs:seeAlso link, and look for someone whose foaf:mbox has the given checksum.
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix : <#>.

:i a foaf:Person;
 foaf:knows [
 a foaf:Person;
 rdfs:seeAlso <http://rdfweb.org/people/danbri/rdfweb/webwho.xrdf>;
 foaf:mbox <mailto:danbri@w3.org>;
 foaf:name "Dan Brickley" ];

Why not just use a URI?

URI + HTTP architecture 1

The hash is an operator which joins a local identifier to a document URI to give a global identifier.

http://example.com/foo#bar

  1. Strip off #bar
  2. Look up http://example.com/foo using HTTP:
    1. Look up example.com  giving 128.0.0.1
    2. Request foo from 123.0.0.1
    3. 200 OK is returned
    4. Parse the result according to the Internet content type
  3. This gives you information about bar

URI + HTTP architecture 2

Post TAG resolution of HTTPRange-14, an optional possible operation is:
given http://example.com/foo/bar

  1. Strip off #bar
  2. Look up http://example.com/foo using HTTP as amended by TAG:
    1. Look up example.com  giving 128.0.0.1
    2. Request foo from 123.0.0.1
    3. You get a redirection 303 See Other response, indicating that the URI did not denote an information resource, but mentioning a new resource http://example.com/foo-schema.rdf
    4. Request http://example.com/foo-schema.rdf
    5. Get a 200 OK response
    6. Parse the  result according to the Internet content type
  3. This gives you information about <http://example.com/foo/bar>
Not recommended by me.
Other issues:  Content negotiation between HTMl and RDF.  LSIDs

HTTP Arch 3:  other links

Various properties used to point to resources which may be interesting.

[MIT work with CWM in this area funded by various NSF and DARPA grants]

Breadcrumbs ethos



Mythbusting

Myth: "The Semantic Web technology is Description Logic"

No, OWL is one semantic web language.

It is important that applications which need different expressiveness can use it.

But other languages must interoperate to the greatest extent possible.

They should use URIs

They should not reinvent functionality already provided by standards.

SW Arch: Same symbols, multiple languages


architectural layers

Mythbusting: Not just public data


Its like a metro, the way the lines of common concepts connect the stations of different applications


For example in biopax

When will the patterns all connect?Venn diagram showing ontologies overlapping by certian common terms

[Diagram: Joanne Luciano,Predictive Medicine; Drug discovery demo using RDF, Sideran Seamark and Oracle 10g]

Other myths


The fractal tangle


Total Cost of Ontologies (TCO)

Assume :-) ontologies evenly spread across orders of magnitude; committee  size as log(community), time as commitee^2, cost shared across community.
Scale Eg Committee size Cost per ontology (weeks) My share of cost
0 Me 1 1 1
10 My team 4 16 1.6
100 Group 7 49 0.49
1000 10 100 0.10
10k Enterprise 13 169 0.017
100k Business area 16 256 0.0026
1M 19 361 0.00036
10M 22 484 0.000048
100M National, State 25 625 0.000006
1G EU, US 28 784 0.000001
10G Planet 31 961 0.000000

Total cost of 10 ontologies: 3.2 weeks. Serious project: 30 ontologies, TCO = 10 weeks.
Lesson: Do your bit. Others will do theirs.
Thank those who do working groups!

User Interface challenges

User interfaces are blossoming at ISWC (conphoto, &c), and more to do

Rules Interchange Format Working group



Goals for Rules

Web attitude



Thank you

The conference is over. Welcome to the conference!

slides:

http://www.w3.org/2005/Talks/1110-iswc-tbl/

Tim Berners-Lee

CSAIL, MIT




END

You have gone too far.

Clients of the RDF bus

New data applications can be built on top of RDF bus, for example:

db to sw

Components: Adapting random files

Keep your existing systems running - adapt them

db to sw

Components: Triple store

Virtual severs actually figure stuff out as well as look up data

db to sw

Adapting SQL Databases

Keep your existing systems running - adapt them

db to sw

Adapting XML

Remember- RDF on an HTTP server can always be virtual

db to sw

Adapting XML: GRDDL

Remember- RDF on an HTTP server can always be virtual

db to sw

Components: Smart servers

Virtual severs actually figure stuff out as well as look up data

db to sw