The Semantic Web from 30.000ft

Frank van Harmelen

Creative Commons License: allowed to share & remix,but must attribute & non-commercial

http://www.youtube.com/watch?v=tBSdYi4EY3s

The Semantic Web =a big engineering effort +

a set of information structuring principles

People

Web

Machines

HOW?

The Current Web of text and pictures

a web page in English

aboutFrank

And this page is about

LarKC

and another web page

aboutFrank

And this page is about

Stefano

This page is about the Vrije

Uniersitei

linked web-pages, written by people, written for people, used only by people...

Many of these pagesalready come from data,that is usable by computers!But we can’t link the data....

?

? ?

?

The Future Web of Data

?

linked data,usable by computers!useful for people!

P1. Give all things a name

P2. Relations form a graph between things

P3. The names are addresses on the Web

x T

[<x> IsOfType <T>]

differentowners & locations

<village>

P1+P2+P3 = Giant Global Graph

P4. explicit & formal semantics

• assign types to things• assign types to relations• organise types in a hierarchy• empose constraints on

possible interpretations

What’s it like to be a computer on the web?

Examples of “semantics”

Semantics = predictable inference

Frank Lyndamarried-to

• Frank is male• married-to relates

males to females

• married-to relates 1 male to 1 female

• Lynda = Hazel

lowerbound upperbound

Hazelmarried-to

Did you get anywhere? (1/2)

already many billions of facts & rules

Encyclopedia

Encyclopedia

Geographic names (millio

ns)

Geographic names (millio

ns)

names of artists

& art works

(10.000’s)

names of artists

& art works

(10.000’s)

scientific bibliographies

scientific bibliographies

hierarchical dictionaries

(UK, FR, NL)

hierarchical dictionaries

(UK, FR, NL)

life-sc

ience databases

life-sc

ience databases

any CD ever recorded (almost)

any CD ever recorded (almost)

May ‘09 estimate > 4.2 billion triples + 140 million interlinksMay ‘09 estimate > 4.2 billion triples + 140 million interlinks

basic facts on every country

on the planet

basic facts on every country

on the planet

common sense rules &

facts (100.000’s)

common sense rules &

facts (100.000’s)

It gets bigger every month

25 billion facts & relations…

Real life examples• handcrafted

– music: CDnow (2410/5), MusicMoz (1073/7)– biomedical: SNOMED (200k), GO (15k),

Emtree(45k+190kSystems biology

• ranging from lightweight – Yahoo, UNSPC, Open directory (400k)

to heavyweight (Cyc (300k))

• ranging from small (METAR) to large (UNSPC)

Did you get anywhere? (2/2)

Did you get anywhere? (3/2)

used by• media: BBC, Reuters, New York Times, • governments• retail (10K companies):

BestBuy, Sears, Kmart, Volkswagen, Renault• IT: IBM, Oracle• Search: Bing, Yahoo, Google

(before May 2012, after May 2012)

Any lessons?

heterogeneityis unavoidable

Much heterogeneityis solved socially

knowledge obeysa long-tail distribution

Types

Semantic Web from 30.000ft ?

It’s not yet very well understood

It’s a surprisingly successful engineering effort

It’s a handful of principles