EMPOWERING DISABLED USERS THROUGH

THE SEMANTIC WEB

The Concept Coding Framework an application of the Semantic Web

Andy Judson, Nick Hine

Division of Applied Computing, University of Dundee, Dundee, Scotland

Mats Lundälv

DART, Regional habilitering, The Queen Silvia Children’s Hospital, Kruthusgatan 17, Göteborg, Sweden

Bengt Farre

RigAB/Androtech, Göteborg, Sweden

Keywords: Internet Computing, Accessibility Issues and Technology, Semantic Web, Personalized Web Sites and

Services

Abstract: The World Wide Web offers many services from typical textual web content to shopping, banking and

educational services, for example, virtual learning environments. These technologies are inherently complex

to use, but in their very nature offer many benefits to the disabled person. The traversal of the web relies

upon the cognitive skills of the user. You need to know what you want to do. You need to understand what

the site is allowing you to do, and you need to be able to complete the task by interacting with the website.

The emergence of the semantic web offers the potential to reduce the cognitive burden of understanding

what the site can do and how to complete a task, whilst also offering new solutions to typical accessibility

issues. In this paper, we aim to present how the semantic web can be used to enhance accessibility. Firstly

we’ll give some examples of what is currently possible. Secondly we’ll motivate some research initiatives to

enhance user independence for the disabled person, particularly those that use Augmentative and

Alternative Communication (AAC) systems and/or are Learning Impaired.

1 INTRODUCTION

The World Wide Web offers many services from

typical textual web content to shopping, banking and

educational services, for example, virtual learning

environments. These technologies are inherently

complex to use, especially when navigated through

alternative devices (Huang & Sundaresan, 2000;

Sloan, et al, 2000), but in their very nature offer

many benefits to the disabled person.

Disabled users of the web are more common

an many might believe with one in three families

in the world touched by disability (Theofanos &

Redish, 2003). Their article, Bridging the Gap

continues to make some critical points, i. the number

of people with disabilities and disposable incomes is

likely to increase; ii. users with disabilities spend

more time logged on than non-disabled users; and

iii. the internet opens up many barriers and provides

enhanced independence freedom for people with

disabilities.

The internet is currently a web of links, the

trav

ersal of which relies upon the cognitive skills of

the user. That is, they need to know what they want

to do, they need to understand what the site is

allowing them to do, and they need to be able to

complete the task by interacting with the website.

The current focus of web accessibility is that of

e interaction problem, i.e. the navigation of a site.

The emergence of the semantic web offers the

potential to reduce the cognitive burden of what the

site can do and how to complete a task, whilst also

offering new solutions to typical accessibility issues.

162

Judson A., Hine N., Lundälv M. and Farre B. (2005).

EMPOWERING DISABLED USERS THROUGH THE SEMANTIC WEB - The Concept Coding Framework an application of the Semantic Web.

In Proceedings of the First International Conference on Web Information Systems and Technologies, pages 162-167

DOI: 10.5220/0001227801620167

 SciTePress

The semantic web is a framework for data to be

reused across different applications and boundaries.

It is an extension of the current web that provides

machine-readable information whose meaning is

well-defined by standard protocols. (Berners-Lee,

2003). Much of the semantic web research and

development is focused on either the business

opportunities, on knowledge management, or test

environments to explore ideas and tools, for

instance, “Friend of a Friend” (FOAF). Little so far

has been explored that focuses on the end the user,

particularly the disabled user. In this paper, we aim

to present how the semantic web can be used to

enhance accessibility, firstly with what is currently

possible, and secondly to motivate the research to

enhance user independence for the disabled person,

particularly those that use Augmentative and

Alternative Communication (AAC) systems and/or

are Learning Impaired.

2 BACKGROUND

Augmentative and Alternative Communication

(AAC) users are persons with a speech impairment

that is a result of a congenital (eg. Cerebral Palsy) or

acquired dysfunction (eg. Multiple Sclerosis, or

Aphasia following a stroke). People with these kinds

of disabilities have a range of impairments that are

usually a combination of sensory, physical,

cognitive and speech problems. (Edwards, 1995).

A typical task that adults do, for example,

organising travel can be very complicated for a

disabled person. They need to know about physical

access to the hotel, disability friendly amenities and

the flight arrangements will need to accommodate

their special needs. Could the semantic web make

the burden of arranging this trip much simpler? We

could envisage a time when the disabled user should

be able to tell a search engine, “I want to attend the

ISAAC conference in Brazil” (International

Conference of 2004 on Augmentative and

Alternative Communication). The user’s agent /

browser would then return options ready to purchase

with the flights, hotel arrangements, and all special

requirements already filtered based on a user profile

that, for example, takes into account their physical

or dietary needs. The architecture of the semantic

web is intended to do just that. The user’s agent will

be able to ask intelligent questions of a website. The

solution will be provided from the rules and the

ontologies that the website uses, and these can

bridge different domains, all interoperating

seamlessly. This is currently a vision of the future,

an anticipated result of the emergence of the

semantic web. For now though, we can exploit the

semantic web with applications of it in constrained

domains to address access issues previously

neglected.

The AAC user needs a communication aid to

interact with others in everyday situations. These

systems may be populated with a variety of

symbolic representations of language concepts

(abstract entities / meanings). For instance, the

sequence of concepts, “I, belly, yesterday, (to) hurt”

could be interpreted as “I had a sore belly

yesterday”. This form of communication is common

for symbol users and each of the concepts could be

represented as a symbol on the users’ device as

shown in Figure 1, where four different symbol sets,

Bliss, PCS, Pictogram and Beta are used (in rows,

top-to-bottom) to show how they would each portray

the same message.

Figure 1: “I had a sore belly yesterday”,

represented in Bliss, PCS, Pictogram and Beta.

Referencing to and exchanging between

proprietary, symbols

encoded messages, becomes

problematic in Internet environments. For example,

if Andy constructs a message using his English PCS

symbol vocabulary and sends it via email to his

friend Mats, a person who uses Bliss and lives in

Sweden, then Mats may wish to read the message in

Swedish Bliss representation, that is his personal

graphic symbol and language preference. Such

translation on a concept-by-concept basis presents a

number of problems for the user. For instances

Mats’ replacement symbol language, Bliss may not

include equivalent representations of the PCS

concepts used by Andy, or may have two or more

representations of the same concept. These

difficulties are caused by a lack of common

practices in the definition of concepts for graphic

symbol systems in general, and concept encoding

EMPOWERING DISABLED USERS THROUGH: The Concept Coding Framework an application of the Semantic Web

163

schemes in particular. The development of a

Concept Coding Framework (CCF) intends to

change that.

The CCF is designed as an application of the

Semantic Web. It will offer AAC users enhanced

accessibility of the Internet and will remove barriers

for message exchange. The Semantic Web as a

whole potentially offers these same users more

support and independence. This all sounds great in

theory, but developing such solutions is very

complicated, and will be a rather long-term

commitment. This is clear from the rate of progress

with the Semantic Web itself. Development started

with Tim Berners-Lee’s road map in 1998, by

February 2001 we had an Activity Statement from

the World Wide Web Consortium (W3C) Semantic

Web Initiative and in February 2004 we saw the

Resource Description Format (RDF) and Web

Ontology Language (OWL), (the backbone to the

Semantic Web) become standard technologies of the

W3C.

3 REPURPOSING CONTENT

Users of AAC systems experience significant

difficulties when interacting in the text-rich Internet

environment. Web accessibility experts feel Internet

users with learning difficulties present an especially

complex challenge (Seeman, 2002; Clark, 2003).

The existing Web Content Accessibility Guidelines

(WCAG) from the W3C, WCAG 1.0 clearly focus

on the visual impaired users, but the emerging

guidelines, WCAG 2.0 are certainly taking more

notice of the other groups of users, as more groups

of accessibility experts focus or specialise, for

instance, in Learning Difficulties (LDWeb). Existing

solutions or recommended techniques say amongst

other things, “use plain language”, but even this idea

is vague and how this could be achieved is still

debated in many accessibility forums and discussion

threads. With the emergence of new technologies as

part of the Semantic Web Initiative we now have the

capabilities and potential to start to address the

issues of web accessibility for persons with learning

difficulties (Seeman, 2004). With time, we should

see user agents that can fulfil the vision of simpler

travel as outlined above.

Jakob Nielsen’s Alertbox article “Alternative

Interfaces for Accessibility” (Nielsen, 2003)

describes the conflict between practical and ideals

when implementing a perfectly usable design.

Neilsen states that the practical solution chosen

through cost and maintenance is to provide a “single

design for multiple audiences”; where as the ideal is

to provide “separate designs optimized for each of

main access modalities”. This ideal is achievable

through the technique of separating content from

presentation; hence the prolific development of

Cascading Style Sheets (CSS), whose power in

terms of accessibility is driving many online

accessibility communities to deliver beautiful and

highly accessible content.

The Concept Coding Framework is a new

potential solution that is being specifically

developed to provide a mechanism for repurposing

content into preferred symbolic representations

through the use of semantic web technologies for the

AAC user. This is an opensource and international

initiative that resulted from the pan-European

WWAAC project, which aimed to enhance access to

the World Wide Web for the AAC user through

various routes (Lundälv, et al, 2003; Poulson &

Nicolle, 2003; Magnuson & Hunnicutt, 2003).

Concept coding offers an extra level of

separation - that of the actual meaning of the content

from its representation. So in addition to the text in

the HTML paragraphs, RDF annotations are

provided that map the words in the text to their

generic concepts. It is then the responsibility of the

user-agent, for example, the user’s web browser, to

parse the annotations and thus repurpose (on the fly)

the textual content into their preferred language, and

if necessary symbolic representation. Lisa Seeman

of UB-Access is also investigating the use of the

Semantic Web to repurpose material into an

accessible form suitable to users via a system known

as the Semantic Web Accessibility Platform

(SWAP). SWAP uses a proxy server to translate

content into a form that suits the users’ profile,

however, it does not look at the AAC user.

3.1 Concept Coding Framework

Many AAC systems use some kind of graphical

symbols to represent a limited vocabulary of basic

concepts. However, there is a lack of widely

accepted standards for the language, concept,

symbol, and encoding schemes of these

vocabularies. This then means that translation

between the different vocabularies and text is

difficult.

The CCF provides a foundation for, and a bridge

between, current and future proprietary AAC

systems, by supporting effective graphic symbol

usage, exchange and maintenance in the context of

standard Internet information sharing. To be

acceptable as mechanism for exchanging messages,

concept codes should be:

• Clearly defined, harmonising where possible,

with the emerging principles for general

concept management in the Internet.

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• Non-Proprietary and publicly accessible.

• Exchangeable over the web.

• Culture and language independent.

• Simple and straightforward to implement.

• Provide clear benefits for end-users.

As with any other language, symbol sets are

dynamic entities, families and professional carers

supporting AAC users are likely to need or want to

understand the technical complexities of such a

system. Therefore, there is a requirement for

mechanisms to support the framework, such as, a

facility for the addition of new concepts, and the

maintenance of the ontologies (a database of terms

used to describe and represent an area of knowledge,

in this case language.

To achieve this, the proposed CCF must rely on

a stable foundation of concepts with unique IDs

referring to one or more Reference Ontologies where

the concepts are clearly defined – including their

relations to other concepts. It is strategically

essential that there is a rich and thoroughly defined

natural language ontology at the root of this

construction.

The Base Reference Ontology (BRO) contains

around 4000 - 12000 concepts that are a subset of

WordNet, an electronic lexical reference system

(Fellbaum, 1999), supported by a small

Complementary Reference Ontology (CRO) of

about 200 - 1000 common function words and

specialized concepts not covered by WordNet.

Figure 2 illustrates the structure of the proposed

framework. The CCF is built up of 3 parts connected

by a Bridge. These are:

Figure 2: Concept Coding Framework

Structure Overview

2. The Concept Code Definitions (CCD) acts as a

controlled vocabulary of concepts currently

supported by the CCF. Each concept is defined

by its own unique ID, and through references

into the Reference Ontologies.

3. The Base Reference Ontology (BRO), which

contains the concepts and their definitions,

including relevant parts of the hierarchy,

relations and some linguistic information. This

resource is currently derived from WordNet,

but alternative or complementary ontologies

may potentially be utilised.

4. The Complementary Reference Ontology

(CRO), which contains the concepts currently

not found in WordNet (primarily around 200

common function words, such as pronouns,

prepositions, and question words). These

concepts are grouped in simple hierarchies,

with other relational and linguistic information

corresponding to that of the BRO.

Each proprietary ontology owner who wants

their users to benefit from the CCF will have to take

on the responsibility to create a mapping between

the concepts in their own ontology and the concept

codes in the CCD, the entry point into the

framework. The APIs and a CCF Template Bridge

are being developed as part of the Framework to

support the mapping process.

An alternative view of CCF is a nerve spine,

with each proprietary system tapping in & out of it

(See Figure 3).

Figure 3: Concept Coding Framework

Spine Visualisation

The large column on the left is the CCF. The

CCD is the nerve stem running down the spine to the

BRO coupled with CRO that form the base of the

column. Vendors (e.g. Widgit and Handicom) then

create a mapping from their respective Assistive

Ontology onto the CCD. These Assistive Ontologies

are then linked into the CCF, allowing requests to be

routed between them (e.g. between Widgit and

Handicom concepts).

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In a similar manner different natural language

lexicons, providing additional text representations,

may be related as Assistive Ontologies. Note: The

English one is already present as part of the

BRO/CRO.

3.2 Concept Coded Documents

We will not define a new document format or

specify one to use as that would go against all

principles of the web and steer us into proprietary

formats. Instead, we suggest the use of RDF (W3C,

RDF) coupled with other technologies, namely

OWL (W3C, OWL), XPointer (W3C, XPointer) and

Ruby Annotation (W3C, Ruby Annotation) as a

means to provide concept coding to existing

document formats. For example, imagine a very

simple webpage that just contains the text “I want a

cup of coffee”. One way, and probably the tidiest for

adding concept codes, is to link in a mapping file of

the concept codes and representation references

from the document header.

The linked, RDF/XML file contains the concept

code references for the text in the html, after some

initial declarations of namespaces, each word or

phrase would be mapped by an XPointer to its

concept code in the CCD, and possibly some

alternative representations, for instance Bliss, as

shown in the following “coffee” RDF example

snippet.

The Standard Bridge is then used to map this

definition to entries in the BRO and/or the CRO.

Then, for instance, the Reference Ontology would

contain an entry that has a text representation of the

concept and possibly refers back to the original

WordNet ontology. In this example there would also

be a Bliss extension of the Bridge that maps the

concept code to a code in the Bliss Assistive

Ontology.

4 ENHANCED INDEPENDENCE

Everyday tasks such as shopping for groceries may

be a complex and tiring rigmarole for the disabled

person. Online shopping may provide many benefits

to this user group, but using these services is still

very complex and hard work. This Christmas, online

spending was expected to include 43% of consumers

in the UK (BBC News, 2004). There is a move from

the high street to eRetailers. There is also a move of

shoppers from eRetailers with the cheapest product

to eRetailers with better service, websites and

customer reviews. Indicating that some customers,

according to individual preferences and

prerequisites, in some instances are beginning to

prefer shopping online to traditional shopping. It

also indicates the need for eRetailers to improve the

accessibility to their services – for customers in

general and for disabled users in particular.

The Aurora (Huang & Sundaresan, 2000) system

was a proxy facility to address the issues of

comprehension and navigation as faced when using,

for example, an auction site like eBay. However,

their system was developed pre Semantic Web. They

relied upon manually made custom profiles of sites

to allow each facility to be successfully re-purposed.

The Semantic Web can potentially reduce

barriers of understanding and provide enhanced user

independence. But this is still a long way off, and

poses “the grand challenge for the current generation

of computer technology” (Embley, 2004).

The CCF will form the basis of a number of new

research and opensource development initiatives that

will take concept coding to another level of

sophistication and flexibility. A demonstrator exists

that allows you to explore a test framework, which

includes a facility for composing simple messages

that can translate to different symbol sets.

Eight million disabled European citizens with

language disability (about 20% of the current total

disabled population) are not, or are in only a very

limited manner able to make use of the possibilities

that modern information technology provides. The

challenge of the WWAAC project has been to make

the Internet more accessible, thereby increasing the

quality of life for this target group of users.

<rdf:Description

rdf:about="#xpointer(‘coffee’)">

<ccf:conceptCode

rdf:resource="&ccd;CC-COFFEE-

1000"/>

<ccf:representationItem

rdf:resource="&iso-bliss;13373"/>

</rdf:Description>

With the help of European Community funding

it has been possible to start to develop an open

source standard. The CCF can through

standardisation enable users to be more active

members of the society. The CCF when matured will

assist their education, independence, and

employability.

5 FUTURE WORK

The developments of the Concept Coding

Framework show that it is possible to create a

common bridge between various graphic symbol

systems and textual languages. This is definitely a

step in the right direction as a solution to providing

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understandable content. The CCF can bridge

between different technologies and products

developed for AAC users and also between Assistive

Technologies (AT) and the mainstream technologies

of today. In the future, assistive devices employing

CCF technologies will be able to exploit the

Semantic Web in numerous ways. For instance, their

user agents could roam the web on a mission to

perform sophisticated tasks, like a organising a trip,

for them in an automated manner.

Future work of the CCF Interest Group is

focused on the delivery of tools and plug-ins for the

development and support of the framework.

Particularly, the objective is to develop and evaluate

a full-scale vocabulary (CCD), supported by a large-

scale repository of ontologies (BRO, CRO and

Assistive Ontologies). It is vital that this work is

performed in co-operation with key vendors and

stakeholders of the field.

ACKNOWLEDGMENTS

We are grateful to the contributing members of the

Concept Coding Interest Group, particularly Charles

McCathieNevile and Lisa Seeman; also David Sloan

and Saqib Ashraf for their advice and comments in

the writing of this paper.

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