TitlePages - Preamble - Introduction - Accessibility - UniversalAccessibility - PostProduction - Metadata - Accessibility Metadata - PNP - DRD - Matching - Interoperability - Conclusion - References - Appendix 1 - Appendix 2 - Appendix 3 - Appendix 4 - Appendix 5 - Appendix 6 - Appendix 7 - Appendix 8 - Appendix 9 - Appendix 10 - Appendix 11
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 Australia License.
© 2008 Liddy Nevile
Given the Dublin Core as a huge base for international, cross-domain metadata, it seemed obvious when the research started with accessibility and metadata that the two should be combined. Given the number of Web services that adapt resources for users, it was assumed that they would be described by some sort of metadata that could be transformed for use as AccessForAll metadata. The first section of this chapter, therefore, reports on some available alternative resources and the liklihood that they could yield the necessary metadata. The next exercise was to find out if there are Web services that adapt or transform content, if there is a way to choose to have this done. Some typical services were considered. Finally, there is some discussion of why the Dublin Core metadata communities, who are responsible for much of the interoperable metadata in the Web world, have an interest in accessibility metadata, and that interest itself.
The aim of this chapter is to provide the final pieces to complete the context in which the development of AccessForAll accessibility metadata is explained.
There is always, in the mind of metadata experts, experience that shows that metadata is expensive to produce and that it is very often inaccurate. For this reason, it is important when proposing a new use or context for metadata, to be sure that it is necessary, not overly-complicated; that it will, in fact, be created and used. This section locates the current research in a world that is already partially prepared for it. Showing that there is a substantial amount of discoverable material in a range of formats suitable for people with varied needs and preferences is important if there is to be more work in finding a way to describe the necessary needs and preferences and the resources that might satisfy them. Thus, the quantity of discoverable material is indicated within this section. In addition, unless the new descriptions can be used alongside those already in use, that is, unless there are existing descriptions that are interoperable with the new ones, there is not much point in undertaking the research. What follows shows that there is sufficient material and it provides a base with which the new metadata should be interoperable.
In the United Kingdom, the Royal National Institute for the Blind (RNIB) has developed and maintained the National Union Catalogue of Alternative Formats.
Ann Chapman (2000), says that 5% of the 100,000 new British titles published each year are converted into alternative formats. She points out that these formats are created by a range of individuals and organisations and made available in a number of different ways and places. Her interest is in an interoperable library catalogue of such alternative formats. In 1989, the Royal National Institute for the Blind (UK) R.N.I.B. began the process of computerising its card catalogues, thereby creating the National Union Catalogue of Alternative Formats.
As part of the Department for Culture, Media and Sport funded programme to improve library and information services to visually impaired people, the role of NUCAF was reviewed in 1999 (Chapman, 1999). The review concluded that a national database of resources in alternative formats was an essential tool in service provision and that while NUCAF in its present form had limitations, particularly in respect of access, it did provide a good basis for a more comprehensive database of resources." ...
It further recommended that the new database should primarily cover the output and holdings of the specialist non-commercial sector, and that collaborative agreements with existing databases and union catalogues should be developed to cover the commercial sector publications." The review pointed out that, "In addition to libraries, a range of agencies (doctors, dentists and health professionals, banks, advice centres, electricity, gas and water companies, tourist offices, schools and academic institutions, government departments, and service providers of various kinds) would either use the database or refer people to it. Currently visually impaired people and those working to support them are restricted to a few narrow avenues of access to NUCAF. The new database will be designed to be far more widely accessible to end users and library staff. To achieve this it was recommended that the national database should be held on a web-based system, supported by CD Rom and electronic file versions. (Chapman, 1999)
Eventually, as a result of various funding opportunities and projects carried out in a number of places, NUCAF was merged into a new service called REVEAL. In "Project One part A: The future role of NUCAF and a technical specification of the metadata requirements", Chapman (1999) reported "The national database should where possible use national and international standards. It should use the UKMARC format and conform to AACR2. Current RNIB subject indexing should be used for subject indexing, and LCSH entries retained where they exist in the records for the original items. A single set of headings for fiction genre/form should replace the existing ones. A full set of the data elements required has been identified."
These were found to be:
While NUCAF had catalogue records for many items, they were only items converted for the benefit of users with vision disabilities and they did not include representations in all formats or modes of access. Initially, they did not include commercially produced formats and they were expected to be catalogued only so they could be discovered, as was typical of the understanding of the use of metadata at the time (Chapman, 1999). The MARC21 007 fields provide for quite specific information about the form of tactile representation of information such as that it is contracted Literary Braille or 'spanner short form scoring' of music.
Chapman (op. cit, Section 2.4) points out that the existing NUFAC's "only clearly defined objectives are those that relate to stock management and production management at the RNIB. It is therefore difficult for it to satisfactorily address functions outside the RNIB". She asserted that given the difficulties associated with copyright with respect to the transformation of information into alternative formats, the new data base would need to do more. She did not think of computers at that time as being able to automatically decompose information resources and recompose them to suit the needs and preferences of users. Her final recommendations included that, "The database must provide data rich bibliographic records".
At the time, the Library was UK’s most comprehensive collection of material on the subject of visual impairment. The resultant REVEALWEB, at the beginning of 2006, boasted 100,000 resources in accessible formats (2006). This is indicative of the quantity of material that could be made available for use by people with vision disabilities, and therefore all others who are for one reason or another not using their eyes as they might to view content.
REVEALWEB's formats are:
Given the size of this collection of well-described, discoverable materials, it is important that any new metadata descriptions are interoperable with this list. There is every indication that these resource are described with standard metadata and therefore could be used by an AccessForAll service.
The USA also has a union catalogue maintained by the Library of Congress National Library Service for the Blind and Physically Handicapped [NLS]. The Union Catalogue (BPHP) and the file of In-Process Publications (BPHI) can both be searched via the NLS Web site [NLS].
Indicative statistics for the NLS (according to those posted on 2005-01-11) are:
Each year it distributes 23 million books and magazines to a readership of more than 759,000 individuals who cannot read regular print for visual or physical reasons. NLS functions as the largest and frequently only source of recreational and information reading materials and services for a segment of the population who cannot readily use the print materials of public libraries. The NLS International Union Catalog contains 382,000 titles in 22 million copies. (NLS, 2002)
The formats available appear to be press Braille, digital Braille (Web-Braille), audio cassettes, large print text, digital text, maps (tactile), electronic resource, music (Braille), music (large print), and sound recordings (NLS, 2006).
In a fact sheet, NLS explains: "Currently, this service includes the acquisition, production, and distribution of Braille and recorded books and magazines, necessary playback equipment, catalogs and other publications, and publicity and marketing materials" and that, "One of the primary reasons for instituting a national program was to obviate the inevitable difficulty and high cost for individual libraries to acquire books in special formats" (NLS About, 2006). In a sense, this is the same motivation as is being suggested in this thesis for the development of a metadata standard for AccessForAll materials.
The Library of Congress uses standard metadata for this collection of resources. There is therefore, evidence that there are alternatives available for immediate use by people with disabilities and that they are already described by suitable metadata. They could be used by an AccessForAll service.
The American Printing House for the Blind [APH] currently hosts the Louis Database of Accessible Materials for People who are Blind or Visually Impaired. The Louis Database contains over 145,000 titles of accessible materials, in Braille, large print, sound recordings and computer files, from over 200 agencies throughout the United States. The database can be searched via the database Web site and there is a link to the NLS Web site and union catalogue database.
The Canadian National Institute for the Blind operate a number of services including online access to their library collection via VISUCAT. The library collection contains over 45,000 titles with materials in braille, print braille, audio, electronic text and descriptive video. Access to the catalogue is via a telnet connection. Library clients can search VISUCAT, check on titles currently on loan to them and reserve titles.
Vision Australia has a number of services including a database that points to organisations that provide alternative formats. Universities around Australia have in-house units that work on alternative formats for their students.
The relevant organisations clearly have a lot of resources to offer and many of these already have standard metadata describing them. It can be assumed that if such resources can be used more frequently and discovered more generally, their beneficial value will increase and more of them will be made available.
There are two kinds of content adaptation services: those that adapt the components of a resource to fit a given specification and those that in some way adapt the components, such as converting text into Braille. As well as static, or held content, there are services for creating accessible content - some of which work on-the-fly and others which can be used asynchronously. There are any number of such services in the world, but only a few major ones need to be considered here to establish the possibilities.
For some time the Speech-to-Text Services Network [STSN] has been making accessible content alternatives for content that cannot be used by people with hearing disabilities. They describe their three real-time speech-to-text services according to the technology used to process incoming speech:
The STSN has a table that shows differences and similarities among their services. This table also makes clear the sort of services that are valued by people with hearing disabilities. Some of these are relevant in the current context because they represent services that some people will use when they cannot access auditory information.
| Steno machine-based Stenography Systems - CART | Laptop-based Speed Typing Systems | Automatic Speech Recognition Systems (ASR) |
|---|---|---|
| Verbatim, or near-verbatim translation, i.e., word-for-word | Meaning-for-meaning translation, i.e., "all the meaning in fewer words" | Communication access usefulness determined by ASR software error rate, reader's error tolerance, skill of speaker, etc. |
| Typist who is trained court reporter | Typist who is trained in specific system | Trained "Shadow" speaker |
| Info Link CART | Info Links TypeWellC-Print | Info Links ASR, CaptionMic, iCommunicator, Liberated Learning Initiative |
As is apparent from Table 4, human services are provided to render the content accessible to those who are not able to hear it in its original form. Such services exist alongside new ones being developed like those offered and proposed by ubAccess, particularly SWAP that will utilise computers to perform 'intelligent actions' on inaccessible content (Chapter 5).
ubAccess (mentioned in Chapter 5) is an example of an organisation that has developed an adaptation service. The wizard called the Semantic Web Accessibility Platform [SWAP], can transform a given Web page to have characteristics that will suit users with special needs. As this service depends upon knowing the users' needs, it is appropriate for it to be considered as an example of the type of service that will be supported by the AccessForAll approach to accessibility.
There are many services that are built into content servers that could be described as adapting content, or components of aggregate content, into suitable composites for users. In general, these are driven by the device and software requirements. The materials delivered to a telephone by a standards compliant browser will at least attempt to adapt the resource for that device. For example, the Opera browser can present the user with a newspaper page in a way that makes sense to someone with a very small screen, as shown in Figure 45. Opera has recently released a browser for general use that contains a screen reader (ref???).
The early Dublin Core accessibility work is relevant because it cleared the way for the AccessForAll approach that has become the main work of that group.
The Dublin Core Accessibility Working Group was founded in 2001 to investigate the use of metadata in accessibility work (DC Accessibility Working Group, 2001). There was a follow-up joint Meeting of the W3C/WAI Interest Group and the IMS Accessibility Working Group in Melbourne, Australia, in November 2001 (WAI-IG, 2001). The aim, at the time, was to be proactive in setting an accessibility agenda for content developers by bringing to their attention the need for accessibility, as much as to provide functional metadata. Some time later, as a Director of DCMI, Eric Miller strongly defended this position at a meeting of the DCMI Advisory Committee (as it was then), where there was general support for the work.
The early work on the AccessForAll approach has been described. Now the special requirements for Dublin Core metadata are considered.
The 'rules' for DC metadata have always been that the metadata terms must comply with the Dublin Core information (abstract) model [DCMI DCAM]. That the model has not, until late in 2007, been expressed in an unambiguous way (see further details in Chapter 6). This problem made it very difficult to know how, exactly, to develop conformant Dublin Core metadata. Once the accessibility work left the narrow confines of the DC community and was led elsewhere based on another type of metadata, the best that coulld be done was to ensure that the new metadata matched as closely as possible the DC model, and that it was at least possible to cross-walk without loss from one system to another.
Given the changing nature of the DC model, there were many iterations of the AfA metadata in an attempt to match the DC model but they always seemed to fail to do this. Once the model became stable, it was possible to determine the requirements once and for all and the most recent version of the abstract model of the DC AfA metadata (Figure 46) is conformant to the official DC Abstract Model.
This model and the associated vocabularies have not been formally adopted by DC, which requires the approval of the DC Usage Board, but it has been informally accepted as now matching the rules. Achieving this status required input to the DC process of definition of that abstract model, as well as the development of this one to match it (Chapter 6; Pulis & Nevile, 2006 now online?).
In 2007, Andy Powell had the following to say in the context of educational metadata:
so what does history teach us? Why are we where we are now? I would argue that the "effort aimed at distilling semantics & simplifying them through delivering sufficient consensus across a significant community of practice" essentially failed. It failed because the approaches reached thru that consensus cost more to implement than the benefits they realise in the context of the original use-case (resource discovery on the Web).
When was the last time you found something because it had been described using DC?
What history tells us is that DC is too complex for the 'simple' resource discovery scenarios envisaged when the initiative started. Those scenarios now tend to be catered for by full-text indexing and social tagging of one form or another. At the same time DC is not complex enough for the scenarios typically found in digital libraries, scholarly communication, elearning, commerce and the like.
Yes, the DCMI Abstract Model tends to move us more towards the latter. Yes, explicitly modelling the entities in the world that we want to describe is more complex than not doing so.
Complex but necessary. All IMHO of course.(Powell, 2007)
In a sense, the metadata being proposed for accessibility is very complex but it is meant to be used differently in different circumstances. The typical use of it is with a single term (Dublin Core or other) where the values identify limitations to the perception mode for the content. The adoption of a new Dubin Core term 'accessibility' is in progress [DCMI Access]. This information alone will make a huge difference to discoverability for a user by warning them of inappropriate material, as well as by pointing to appropriate material. With such metadata, when a resource is made or catalogued by experts and designed to satisfy an accessibility problem, those who have developed it can use their expertise to give maximum value, and exposure, to the resource.
The final development stages of the WCAG 2.0 specifications [WCAG-2] have been contemporaneous with the finalisation of AfA as an ISO standard. Convincing the W3C Working Group responsible for WCAG 2.0 to include a requirement for AfA metadata would have made all WCAG 2.0 conformant resources suitable for adaptation according to AfA principles. For a number of reasons this was not possible, not the least being that the WCAG authors were not prepared to simultaneously allow that a resource might be less than conformant to the rest of WCAG and yet 'legitimately' be described by metadata as specified by WCAG. They did consider it important to allow for the use of metadata, however, especially to identify an alternative resource that could be used when that alternative had special features to make it more useful than a standard, conformant resource, and the original was already WCAG conformant. Given the inclusion of this as a technique, there is, of course, no reason why a developer should not provide full AfA metadata and if there are tools that make this easy, it might happen.
The proposed DC accessibility term [DCMI Access]is defined according to the WCAG 2.0 specification of accessibilty in that it recognises and adopts the WCAG 2.0 definition of accessibility [WCAG-2].
In this chapter, the availability of resources that will already have metadata is investigated for two reasons: if there are, in fact, no significant sources of alternative components that are accessible to people with disabilities, there will be nothing to find, and secondly, because if such accessible components do exist, it is important that they are organised and described with electronic catalogues that are capable of providing AfA metadata, even if it needs to be transformed to comply with the interoperable standards. It is critical to have established that the research is not undertaken in a vacuum, but rather in an environment where it can have immediate application.
Dublin Core metadata is central to the research, so the expectations of the Dublin Core community are critical, and understanding their involvement is therefore essential.
In the next two chapters, the metadata profiles developed as the first pair of AccessForAll modules are described.
