The Semantic Web - a useful, usable

technology?Liddy Nevile

La Trobe University

• The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework ( RDF ), which integrates a variety of applications using XML for syntax and URIs for naming. - W3C

• WWW2004 Semantic Web Track and Devday Presentations Online 2004-05-26 ,The W3C Track on the Semantic Web and the Semantic Web Developers Day presentations are now online. These presentations provide a status update on the Semantic Web Activity at the W3C and highlight examples of industry adoption and novel applications using Semantic Web technologies.

• See http://www.w3.org/2001/sw/

• "The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation. ”

-- Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web , Scientific American, May 2001

A use case

• DCMI has elements, terms, schemata, as well as growing sets of documents. All these need to be managed. What happens when new terms are created, when new documents are generated?

• Can the semantic web technology being developed make this nightmare of human management an automated task?

A better question …

• Can metadata become operational so it does some of the things that we have had to do to it in the past?

• Instead of having to develop applications to sort and shift information about, can we get the information to do that work for us?

General Public (on the Web)

Users(with middle wear/

AT / Browsers)

Website

Your Current Website

Semantic Annotations, Automatic Fixes, Database

views Engine

Layer of Meaning

PresentationalLayer

Alternativeversions

Untouchedoriginal

Before….

As see on the Web

Navigation Bar made with images-only. Completely inaccessible to assistive technology.

Relationship between text and form elements inaccessible to assistive technology.

After…(1)

Meaning behind images is known

Relationship between text and form elements is known

Enhanced Navigation for screen readers, PDA’s and orientation

As see on the Web

Middleware Architecture (taken from SWAP)

Original HTML

SWAP MLTranslation rules

Semantic annotations Data Base

XHTML

Scenario-specific transformations XHTM

L

XHTML

XHTMLOriginal

presentationExtract

presentationScenario-

specific CSSRules and

transformations

Semantic web

• Additional layers of information– Provide meanings of terms– Provide relationship information– Links to relevant information– Links to relevant people

• Allow software agents to manipulate this information

• Ontology defines terms

Resource Description Framework (RDF)

• Language for semantic web• Not just machine readable information• Also machine understandable informationeg:<?xml version="1.0" ?>

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:s="http://description.org/schema/"><rdf:Description about="http://www.w3.org/Home/Lassila" bagID="D_001"><s:Creator>Ora Lassila</s:Creator><s:Title>Ora's Home Page</s:Title></rdf:Description></rdf:RDF>

Ontology

• System of concepts and relations between them:– Table [is piece of] furniture– Arm [is part of] body– Japan [is located in] East Asia

• A method for storing and representing knowledge

EGs of types of annotations

• Meaning behind text gaps – text equivalents• Relationship to applications – no frames / functional

equivalents• Relationship between text nodes and form elements -

accessible forms and labels• Structural identification of page elements -

orientation• Role information – this is a data, types of content• Concepts – implied content• Resolving ambiguities and relative importance –

simplifications• Plus interpretation = communication of

knowledge

Relationships and meanings

• This picture has meaning of welcome• This picture is a link to the home page• This color code implies feminine

relevance• This list of links is similar to a main menu• This format is similar to a title• This paragraph is less important for this

user group• The word ‘it’ refers to the table

Components

• an ontology for accessibility

• a authoring tool for creating RDF using this ontology for specific pages

• a user agent that renders accessible pages based on our ontology

• a flexible testing tool

Roles and rel’ships (predicates)

• IsBlock - point to a block of links (is included in V1 of SWAP) and associates a content type

• BelongsToBlock - associates link or section of content with a block (IsBlock) (is included in V1 of SWAP)

• ContentType - associates a section of content or link with a content type

• Header - points to link block header, Can also associate a block of links (sub-menu) with a parent menu, etc

• SubmenuOf - associates a sub-menu with main menu

• Association – Implied meaning behind the content and presentation

Properties

• Advertisement • Warning (less safe) • Off-site • Important • Less important

Annotation Based Accessibility

• Provide conditional alternate content• Address traditionally problematic areas in

accessibility– Interfaces for cognitive / age related disabilities – Summaries, clarifications and illustrations for

these disabilities can be hidden..

• Address emerging accessibility issues– Inaccessible languages– Schemas can be annotated– Elements can be marked as “similar”..

What else can it do?

• Allow anyone to annotate any document with alternatives

• Attach a user profile to alterative content• Concept mapping / sign and symbols • Remove ambiguity in language• Device independence• Knowledge systems integration• Support for internationalization /

localization and translation ….

Quinkan Example 1

• Translation .. service QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

Tommy George inspecting red rock ochre.

"A lot of paintings are made in red."

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Quinkan Example 2

• Objects without explanation

• How is it done?

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“A hand stencil”

SVG images<?xml version="1.0" encoding="iso-8859-1"?>

<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20000303 Stylable//EN" "http://www.w3.org/TR/2000/03/WD-SVG-20000303/DTD/svg-20000303-stylable.dtd" [ <!ENTITY st0 "fill-rule:nonzero;clip-rule:nonzero;stroke:#000000;stroke-miterlimit:4;"> <!ENTITY font1 'font-family:"Verdana";'><!ENTITY size1 "font-size:24;">]>

<svg width="690" height="182" viewBox="130 10 550 220" xml:space="preserve">

<g id="Ebene_x0020_1" style="&st0;"><image width="690" height="182"

xlink:href="data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0aHBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAC2ArIDASIAAhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/

………</g>…..

Quinkan Example 3

• When Aboriginal people meet, they greet each other with lengthy descriptions of their identity and family connections.

• Tom adds his photo.• Mary adds her photo.• The relationship between them is in the

metadata (dc:subject and dc:description)

but it is not operational.

How do we represent families?

• Traditional western ‘family tree’– has-mother, has-father– -> has-grandmother, has-grandfather,

has-sibling,...

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How do we represent families?

• Traditional western ‘family tree’– has-mother, has-father– -> has-grandmother, has-grandfather,

has-sibling,...

• Start with Friend-of-a-friend (FOAF)?

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Graphical cataloguing<rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#' xmlns:NS0='http://quinkan.org/index.html#'> <rdf:Description rdf:about='#red'> <rdf:type rdf:resource='http://quinkan.org/index.html#colour'/> </rdf:Description> <rdf:Description rdf:about='#A0'> <rdf:type rdf:resource='http://quinkan.org/index.html#person'/> <NS0:has-name rdf:resource='#TommyGeorge'/> </rdf:Description> <rdf:Description rdf:about='#AADXEVJJKH'> <rdf:type rdf:resource='http://quinkan.org/index.html#Getty-colour'/> </rdf:Description> <rdf:Description rdf:about='#TommyGeorge'> <rdf:type rdf:resource='http://quinkan.org/index.html#name'/> </rdf:Description> <rdf:Description rdf:about='#r23g67b98i'> <rdf:type rdf:resource='http://quinkan.org/index.html#Q-colour-code'/> <NS0:is-same-as rdf:resource='#098734827'/> <NS0:is-same-as rdf:resource='#AADXEVJJKH'/> </rdf:Description> <rdf:Description rdf:about='#098734827'> <rdf:type rdf:resource='http://quinkan.org/index.html#CIMIcolour'/> </rdf:Description> <rdf:Description rdf:about='#pfgjner25243'>

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and lots more…..

• So how do we understand the semantic web?

The drawers method

The filing cabinet

Metadata labels

RDF Labels

RDF labels for labelsHas father Fred

Has mother Mary

Has father Fred

Has mother not-Mary

Has sister Jean

Has half-sister Jean

RDF Labels

The Yolngu Language Project

Metaphors

• The intelligent links ...• The patchwork quilt …• We can find not only what we want

but about what interests us …

• Semantic Web Best Practices and Deployment Working Group (see http://www.w3.org/2001/sw/BestPractices/

SWeb Task Forces

The following task forces are in progress: • OEP - Ontology Engineering and Patterns

Coordinator: Deb McGuinness • PORT - Porting Thesaurii to RDF and OWL

description Coordinator: Dan Brickley

• WordNET description, notes toward revised description Coordinator: Aldo Gangemi

• WRLD - World View description Coordinator: Jim Hendler

SWeb Task Forces

The following task forces are under discussion to start:

• VM - Vocabulary Management description Coordinator: Tom Baker

• XSCH - XML Schema Datatypes description Coordinator: Jeremy Carroll & (open - XML Schema WG)

• HTML - Embedding RDF in HTML • ADTF - Applications and Demos description

Coordinators: Libby Miller, Brian McBride

SWeb Task Forces

Other task forces that have expressions of interest from WG members include:

• Coping with evolving ontologies • Links to MPEG • Style conventions (naming, namespaces, uri,

rdf:label usage) • Tools index • Ontology Design Issues • Units and measures

Semantic Web Tools

• W3C Co-ordinated activity - see http://www.w3.org/RDF/#developers

(local)

• Thank you.