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