Position paper

1. Background

Over the past several years there has been a significant increase in awareness of the need for Web accessibility and development of policies relating to Web accessibility in Europe. Techniques for implementations have been standardized and benchmark guidelines (Web Content Accessibility Guidelines - or WCAG), have been accepted. However, with the evolution of the Semantic Web and RDF, there is an additional ability and necessity to provide better implementations, interfaces and techniques for accessibility principals and guidelines.

The Semantic Web Accessibility Platform (SWAP ) - uses the advantages of emerging syntax to engineer new and improved interfaces for cognitive disabilities, which supports the graphical representation of the document's lay out, information hiding and simplification.

SWAP technologies creates the robust support needed in traditionally problematic areas such as adequate access for the cognitively disabled. It also solves other crucial accessibility problems, which are emerging as XML usage becomes increasingly prevalent.

SWAP creates alternative renderings of sites, or SWAPviews™ which enable people with diverse special needs to smoothly and easily access the content. SWAPviews™ are developed according to the international accessibility standards of the World Wide Web Consortium (W3C), which provide the basis for Internet-accessibility guidelines and legislation worldwide.

Alternative renderings based on RDF[1] annotations associated with the document, solve the specific issues mentioned above. With SWAP-RDF an author can provide alternative content to any valid XML or HTML document. The SWAP RDF annotation for alternative text, structure, form and meaning allow a document to be rendered accessibly for the user. Renderings can be made available as a public free proxy server

Further extensions of the project includesenabled syntax to support language and semantic referencing, with an end-to-end solution for processing support, including end user interfaces that interpret the knowledge base in a form more useful and appropriate to system and user scenario. These interfaces will be user-friendly to people using different languages, linguistically impaired, or without written language.

Further interfaces for Learning Disabilities

2. What are the Key benefits of annotation based solutions for Learning Disabilites?

2.2 The original rendering is incapable of change, such as when web authors are unable to use simplified language

Example pages



Annotations can replace difficult content for simplified versions. However it is probably a safe guess that it would be impractical to simplify a lot of these type of page were the specific meaning of each word is important in normative documents.

However with alternate the original text does not have to be affected, however its meaning is made clearer by annotations of additional non-normative information.

For example annotations can provide:

  1. Titles and headers for each section
  2. Summary (non normative) for each section of content.
  3. glossary refrences and links to background information

Further a graphical interface can be provided that gives a conceptual view of the document and interactive interface.

For example:

Fig 1, Proposed graphical interface for http://europa.eu.int/smartapi/cgi/sga_doc?smartapi!celexplus!prod!CELEXnumdoc&lg=en&numdoc=52000DC0746

Important note: The interface would be dynamically created for all Europa documents. In other words, this transcoded interfaces are not created separately for each page but would be installed an automatic rendering for all Europa on line documents.

The user would chose events such as clicking or mouse over affect to see

  1. The summary of each topic,
  2. to go to the full text of each topic
  3. to see emphasized words or first paragraph of each topic

2. 5 General advantages of Semantic Web and RDF based accessibility:

The Semantic Web and RDF format used by SWAP™ has the following additional advantages over traditional accessibility techniques:

Simplified, annotated or multimedia content required for accessibility for some, is inappropriate for other audiences.

Compatibility Knowledge-Based Services and the Semantic Web:

In integrating accessibility and the semantic web, accessibility can be moved forward, paving the way for customized accessible searches and intelligent user agents with additional applications. In addition, SWAP™ annotations do not have to be a part of the original document, or even be located on the same server. This allows a caregiver or volunteer to make important sites accessible without the original authors' cooperation. A portal for assistive living and similar applications could then independently create required sites accessible.

4 Further options:

SWAP syntax includes support language and semantic referencing, thatenable the web content to become interoperable across language barriers, so that ambiguous, non-explicitlanguage usage can be, from a machine perspective, unambiguous and hence easier to translate.

Summary of criteria:

To create a format were the following categories of uncertainties can be clarified though attached or referenced electronic information

Additional stages of the project could include:

4. 1 To parsing against a simple language lexicon - Simple language use is important for accessibilities as it helps more people understand text on the web site.

When a word is not found in the lexicon, then the user can either replace the word, or add a glossary entry or supply a link to a definition

4. 2Defining word usage

SWAP ontology can be used to alloweach word to be clearly defined and known. Swap achieves this by allowing acombination of Rules and defaults.


Additional, accompanying information (such as annotations in a header or linked file) would contain lexicon information about the use of language on a page, so that from a machine perspective, the content is specific.

For examples: Word ambiguities would be resolved by generalized links to context-based rules with overriding annotations for exceptions. In solving the word ambiguities the syntactic ambiguity can also be resolved. In our example sentence, Fasten the assembly with the lever, an annotation on the word with that defines it as meaning "using" would resolve the syntactic ambiguity. A potential implementation of this methodology could be an RDF type of annotation such as: This word at this location IS DEFINED as that word at that location, where the term IS DEFINED would itself be defined within the SWAP ontology.

Pronouns would have a second type of annotation. Instead of referencing the pronoun to a lexicon definition, one would reference the pronoun to the noun or object to which it refers, thus resolving the semantic ambiguity. In our example sentence "Start the engine and keep it running", an annotation on the word it, that points to the word engine; would resolve the semantic ambiguity. This can be expressed using the standard RDF type of annotations as: This word at this location REFERS TO that word at that location - where the term REFERS TO would itself be defined within the SWAP ontology.


Assuming that different types of ambiguitiePs can be resolved using the SWAP technique, SWAP as so far described would still not be a practical solution to uncertainties in natural language because of practical constraints of adding annotation to each potential uncertainty. This problem can be addressed through a clear and established set of defaults. In some cases defaults could be expressed as a series of grammatical rules. For example, the default reference for each pronoun can be the preceding noun. A pronoun would only require a separate annotation when it differs from the default. One may supply a default lexicon with default meanings for each word. Cascading lexicons or RDF statements pointing to a separate meaning for any individual word, can override this meaning. Using this information a user agent can render the simplified or translated content correctly.

4. 3 Addressing ambiguities

To identify uncertainties in natural language not included in 2 above (pronouns, the word "it" or "the" etc.) allow the user to identify exactly what is referred to with RDFreferences.

4.4 End user rendering

Though an XSL Transformation or java, supplysimplified and precise rendering to the end user

An important future product and application of SWAP™ technology is in clarifying the uncertainties found in natural language using SWAP Annotations. These are annotations that clarify and provide alternatives for uncertainties found in natural language.

Ambiguous use of language creates problems with translation, misunderstandings and accessibility for cognitive disabilities. Poor or complicated use of language often restricts compatibility of data with semantic based systems. For example, translation and simplification tools often translate words based on a meaning that was not intended by the author. This is particularly common when the word ambiguity cannot be resolved based on context using the surrounding words and grammar rules, but require other knowledge sources to determine the meaning of a sentence. Other examples of problematic language usage include secondary and implied meaning, such as are typical of sarcasm. However, with the evolution of the referencing and semantically aware Web technologies, there is a new opportunity to provide better clarifying information, interfaces and integration with semantic based systems. Yet much of accessibility relies on text or text equivalent for different media that different devices can render. However, if the definition of a device includes apparatus that process the text to a form that is more useful to the user, such as a symbolic rendering, then the requirement for text equivalent becomes a requirement for concept mapping.

Currently, sites intended to be user-friendly to the cognitively disabled rely on the use of simple language, illustrations or symbolic representations such as BLISS (a symbolic language invented by Charles Bliss in 1949). Not surprisingly most otherwise accessible sites are reluctant to do this. However, it is now possible to enable typical Web content to be converted to a simplified or symbolic representation, at the user end. This would require encoding that removes the uncertainties typical of natural language, and to annotate the relative importance of content. Symbolic representations that could then be created include Sign, BLISS and other natural languages used by people with impairments.

ILS annotations created by allow an author to make statements about the content, sections of the content or even specific words. These capabilities are used to by SWAPSpecific translations of non-literal text: Annotations can be used to clarify non-literal, ambiguous or obtuse text. The user agent could then use this information to render an unambiguous version of the content™create vocabularies for accessibility, provide alternatives for content and form for documents. However theSWAP™ vocabulary is being increased to enables ambiguous content, in multi-media Internet formats, to be machine understandable, and interpretable by semantic based systems. The strength of this implementation is the combination of defaults (common standard interpretations, lexicons and mapping of text to concepts), and exceptions (overrides that map text to meanings within a defined area).

Annotations can improve automatic translation of web documents, where the author in their own natural language can clarify uncertainties. This will provide expert automated translation and knowledge processing of web content and remove ambiguities in other documents such as legal documents, instructions, technical writing and the like.

Additionally, this will provide possible applications such as data-mining across languages, correct translation of ambiguous text, simplifications, and more accessible, user-friendly interfaces. These interfaces will be of great assistance to people who use different languages, are linguistically impaired, or without written language.

4.5 Examples of Uncertainties that SWAP can address

The following cases will be resolved through the SWAP solution.[2]

Word ambiguity

Word ambiguity occurswhen a word can have more then one meaning. Word ambiguities are typically resolved based on context using the surrounding words and grammar rules.

Syntactic ambiguity

Syntactic ambiguityoccurs when there is more than one possible syntactic parses for a grammatical sentence. For example, the sentence Fasten the assembly with the lever.This may be either an instruction to fasten the assembly using a lever, or an instruction to fasten the assembly, which has a lever attached to it. With the prepositional phrase with the lever can beattached to the verb or to the noun phrase object. However often a Syntactic ambiguity is caused by a word ambiguity- in our example the wordwith is ambiguous. With  could mean usingor connected to.

Semantic ambiguity

Semantic ambiguityoccurs when other knowledge sources are required to determine the meaning of a sentence.For example, the sentence Start the engine and keep it running, the fact that itrefers to the engine is not inferable from the single clause keep it running. The ambiguity is caused by the difficulty in resolving the pronoun.

Word ambiguities would be resolved by generalized links to context-based rules with overriding annotations for exceptions.


[BLISS] Graphic, meaning based communication system invented by Charles Bliss in 1949.

[WCAG10] "Web Content Accessibility Guidelines 1.0", W. Chisholm, G. Vanderheiden, and I. Jacobs, eds., 5 May 1999. This WCAG 1.0 Recommendation ishttp://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/.

[WCAG20] "Web Content Accessibility Guidelines 2.0", Ben Caldwell, W. Chisholm, Jason White and G. Vanderheiden, eds., 28 August 2002

[RDF] "Resource Description Framework (RDF) Model and Syntax", O. Lassila and R. Swick, eds., 22 February 1999. W3C Recommendation.

[RDF Schemas] "Resource Description Framework (RDF) Schema Specification 1.0", D. Brickley and R.V. Guha, eds., 27 March 2000. W3C Candidate Recommendation.

[Modeling Ambiguity] "Modeling the Effect of Cross-Language Ambiguity on Human Syntax Acquisition", William Gregory Sakas, In: Proceedings of CoNLL-2000 and LLL-2000, Lisbon, Portugal, 2000. http://cnts.uia.ac.be/conll2000/abstracts/06166sak.html

[Resolving Ambiguity for Cross-language Retrieval] "Resolving Ambiguity for Cross-language Retrieval", Lisa Ballesteros, W. Bruce Croft (1998) http://citeseer.nj.nec.com/ballesteros98resolving.html##

[Coping with Ambiguity in Knowledge-based Natural Language Analysis] "Coping with Ambiguity in Knowledge-based Natural Language Analysis" Kathryn L. Baker, Alexander M. Franz, Pamela W. Jordan, Center for Machine Translation and Department of Philosophy (2001) Carnegie Mellon University http://www.lti.cs.cmu.edu/Research/Kant/PDF/flairs.pdf

[Language Ambiguity] "Language Ambiguity: A Curse and a Blessing", Cecilia Quiroga-Clare, Translation Journal and the Author 2003 http://accurapid.com/journal/23ambiguity.htm#

[Linguistic Sources of Ambiguity'] "From Contract Drafting to Software Specification: Linguistic Sources of Ambiguity'' Daniel M. Berry, University of Waterloo, Ambiguity in Natural Language Requirements Specifications http://se.uwaterloo.ca/~dberry/ambiguity.res.html


W3C:The World Wide Web Continuum (W3C) was created to lead the Web to its full potential by developing common protocols that promote its evolution and ensure its interoperability (see appendix for more information)

WAI:The Web Accessibility Initiative is a division of the W3C that is responsible for web accessibility

Web Accessibility Guidelines: These explain how to make Web contentaccessible to people with disabilities (for more information see appendix)

Web Content Authoring Guidelines (WCAG):these are web accessibility guidelines created by the W3C

User Agent:Tools used by the end user(e.g., desktop browser, voice browser, mobile phone, automobile-based personal computer, etc.)

[Priority 1] & [Priority 2] & [Priority 3] : A Web content developermustsatisfy this accessibility checkpoint. Otherwise, one or more groups will find it impossible, difficult or somewhat difficult respectively, to access information in the document.

Conformance Level "A": all Priority 1 checkpoints are satisfied;

Conformance Level "Double-A": all Priority 1 and 2 checkpoints are satisfied;

Conformance Level "Triple-A": all Priority 1, 2, and 3 checkpoints are satisfied;

SWAPTM Wizard: A version of SWAPTM with an interactive user-friendly interface that will provide step-by-step instructions to enable the user to establish a SWAPTM alternate rendering of a site.

CSS:Cascaded Style Sheet - Document that contains the formatting and presentational information of a site

Rules:Conditional statements and clauses that if true, will trigger a specific action

Master Rules: rules that alert an operator to a potential accessibility violation

Markup:codes that are inserted into a document that contains formatting information, processing information or structural information in a machine-readable form.

Markup Language:A protocol of mark-up

HTML: Hypertext Markup Language -a language used for the creation of Web and Internet pages

XML:Extendible Markup Language - a technology or protocol for creating markup languages, primarily for use over the Internet.

Assistive Technologies: Products used by people with disabilities to help accomplish tasks that they cannot perform easily or otherwise.

Adaptive Strategies: Techniques that people with disabilities may use, with or without assistive technologies, to assist in navigating Web pages.

Screen Readers:Software used by individuals who are blind that interprets what is displayed on a screen and directs it either to speech synthesis for audio output, or to refreshable Braille for tactile output.

the Semantic Web Accessibility Platform from UB Access – empowers both existing and planned Websites with new capabilities that provide seamless access to the disabled. SWAP™ is wizard-driven, requiring no prior knowledge of disabled-access issues. The SWAP™ artificial intelligence engine allows alternative renderings of sites, or SWAPviews™ architecture enables seamless integration with software packages and devices, creating a host of mutually beneficial opportunities.

SWAPviews™ - SWAPviews™ have been developed by members of the World Wide Web Consortium (W3C) contributing to the worldwide Internet-accessibility guidelines and legislation (WAI - WCAG), as well as active members of PF working groups, the Dublin Core accessibility group.

[1][RDF] "Resource Description Framework (RDF) Model and Syntax", isW3C Recommendation for a protocol to enable the Semantic Web and add a layer of meaning to the World Wide Web. (See w3.org)

[2] Examples are taken from[Coping with Ambiguity in Knowledge-based Natural Language Analysis]