Web 3.0 The Semantic Web
Hatem Mahmoud Lead Developer, eSpace ExpressionLab.com

Agenda Introduction The Problem Solutions
Applications Summary

Introduction

Every language has its own
Syntax and Semantics

Syntax is the study of
grammar

Semantics is the study of
meaning

Syntax is how to say
something

Semantic is the meaning behind
what you say

Different syntaxes may have the
same semantic: x += y x=x+y

Syntax and semantics are all
about communication

Computers use network protocols to
communicate in networks

The Internet is a huge
network of computers that use TCP/IP to communicate

The Web is a system
of interlinked documents accessed via the Internet

Web browsers use HTTP to
communicate with Web servers

You can view Web pages
and use hyperlinks to navigate between them

People can easily access any
of these documents

This is the largest source
of information ever

This is
Web 1.0

Authors started to use
Ajax

People started to share photos
and videos

People started to interact in
social networks

People started to publish content
in blogs

People started to contribute in
wikis

People started to use tags
and RSS

This is the
Read-Write Web

This is
Web 2.0

The Problem

Web pages are written in
HTML

HTML describes the structure of
information

HTML describes the syntax not
the semantics

If computers can understand the
meaning behind information...

they can learn what we
are interested in

they can help us better
find what we want

This is really what the
Semantic Web is all about

This is
Web 3.0

Today's Web is about
documents

The Semantic Web is about
things

It can recognize people, places,
events, companies, products, movies, etc.

It can understand the relationships
between things

Example?

Solutions

Solution: Top Down

Information analysis, web scraping, natural
language processing

Expensive! human intervention, hard to
maintain, legal issues

Solution: Bottom Up

Embedding semantical annotations into the
data

How?

Available options:
RDFa and microformats

RDFa

RDF is
Resource Description
Framework

RDF is a W3C standard
for describing resources in the Web

RDF identifies things using URIs
(Uniform Resource Identifiers)

RDF uses simple statements (Triples)
to describe things

Thing-Property-Value
Subject-Predicate-Object

RDF graph
representation

RDF/XML

N3
(Notation3)

RDFa = RDF in attributes

RDFa provides a set of
XHTML attributes that express RDF data

Example:
Alice in Semantic
Wonderland

Alice is a blogger who
publishes articles at http://example.com/alice

She wants to declare the
license of her work

She wants to specify title
and creator of an article

But there are no such
attributes in XHTML

She can use Dublin Core
vocabulary Dublin: Dublin, Ohio, USA Core: only the core elements of metadata

She wants to give Bob
proper credit when she posts his photos

She wants to display her
name, email and phone

She can use
Friend-of-a-Friend
vocabulary

She wants to list her
friends

SPARQL (SPARQL Protocol And RDF
Query Language)

SPARQL is a query language
for RDF data

You can search for "friends
of Alice who created items whose title contains 'Bob'"

microformats

microformats are simple conventions for
embedding semantics in HTML

designed for humans first, and
machines second

No namespaces,
No new tags

Built upon existing standards vCard,
iCalendar, Atom, etc.

hCard (HTML vCard) represents people,
companies, places and organizations

hCalendar (HTML iCalendar) Represents calendar
events

hReview Represents reviews of products,
services, businesses, events, etc.

hResume
represents resumes

Applications

YahooTech uses hReview for product
reviews

LinkedIn uses hResume
for resumes

YahooUpcoming uses
hCal for events

Challenges! tools, privacy, trust, applications,
devices

Summary

“I have a dream for
the Web in which computers become capable of analyzing all the data on the Web” Tim Berners-Lee, 1999 Inventor of the Web

The Semantic Web is not
a separate Web but an extension of the current one

It is really happening
today

Resources

Thank You! Hatem Mahmoud Lead
Developer, eSpace ExpressionLab.com