The properties and limitations of assistive technology for people with visual impairments

History

2. Computer-Related Applications

2.1 In the late 1970s assistive technology software and hardware were developed to convert ASCII and other languages into braille and to allow on-screen magnification. Such was the success of these technologies that for a short time the terms "blind" and "computer programmer" were linked in the same way as "bacon and eggs" or "peaches and cream". The environment was text-based and most enterprises used bespoke line-entry programming.

At this time, the pattern of assistive technology production developed with the following characteristics:

Small businesses;
High R&D costs;
Iterative accretion of code for 'bug fixes' and upgrades;
Fragile support;
Public sector purchasing for education and employment.

2.2 The major crisis occurred with the move to the graphical user interface (GUI). Microsoft took an early decision not to integrate assistive features in its operating system and applications (e.g. braille translation, screen magnification) but to make its code available to assistive technology developers. It moderated this policy in the late 1990s by providing an "Accessibility Wizard" but this only provided minimum assistance so as, it said, not to put assistive technology developers out of business.

The assistive Technology sector developed "screen readers", notably the JAWS series, to provide synthetic speech and refreshable braille and, by extension, braille embossing; and screen magnification improved.

2.3 In spite of problems, the benefits of assistive technology were enormous because any text could be rendered into braille or modified print.

The limitations of the new developments, however, were significant:

The absolute advantage was clear but comparative disadvantage widened;
The high cost limited purchases to the rich and those fulfilling public sector objective such as education and employment.

2.4 World Wide Web

With the arrival of the World Wide Web the potential and barriers to accessibility were readily understood and in 1997 the World Wide Web's Web Accessibility Initiative (WAI) [iii] was established to set voluntary pan industry standards. The two core principles of WAI were:

Uniform tagging and coding in HTML (later XML);
Description of graphics (alt tag; long desc).

These two principles implicitly recognised the major problems facing VIPs:

Poor HTML or the use of other programming methods;
The increasing use of graphics.

2.4 The failure of the generic ICT sector to integrate accessibility into its software and hardware was critical. It would have cost little to include speech synthesis, braille translation tables and a high degree of on-screen customisation into products at the initial design stage. The VI sector was therefore expected to:

Pay the additional costs for assistive technology hardware and software;
Pay the additional support costs, including a lower mean time between faults (MTBF) resulting from incompatibilities which the generic and assistive sectors blamed on each other, just one small piece of collateral damage from the monopolistic Microsoft client side model.

2.5 WAI committed itself to defining standards in three main areas:

Web Content Accessibility Guidelines;
User Agent Guidelines;
Authoring Tools Guidelines.

Although the development of Authoring Tools Guidelines should have been by far the most significant in developing good practice in designing and coding web pages, the greatest emphasis was placed in the Accessibility Guidelines.

2.6 It soon became clear that there were a large number of barriers to accessibility:

Untagged layout;
Clutter;
JavaScript/Macromedia Flash;
Refreshable/scrolling text;
Inconsistent command routines.

a) Untagged Layout.

Whereas a person looking at a screen takes in the whole array and decides on a lexical order of accessing the text, or simply chooses one element to which the eyes are deliberately directed by the author's design, a screen reader needs to follow a tagged lexical order. A VIP using synthetic speech might:

Follow a list of elements set left without knowing that there is another list to the right;
Be forced to scroll through a mass of repeated metadata before reaching the new information on a page;
Get lost in a table.

In many organisations the web site was regarded primarily as an aesthetic product rather than as a marketing tool. Most web pages do not have consistent taxonomy but mix navigation with links to data.

b) Clutter

Home pages rapidly became icons of corporate hubris. A prime example is the most used home page in Europe, that of the BBC [iv]:

You can see that the main television and radio channel access is buried deep in an array of other elements.

There are now features such as "skip to content" but many sites lack these features.

In 2000 [v] I proposed that taxonomy should be consistent and that it should consist of no more than nine classes, both to simplify accessibility and to accord with numeric keypads. Later I modified this to propose the use of no more than nine classes for high level selection with the use of SMS for the 'last mile'. Some sites have search boxes but many do not. VIPs, swamped in complex pages, often prefer search boxes to scrolling through pages.

c) JavaScript/Macromedia Flash.

There was a highly negative reaction to the use of JavaScript's and Macromedia flash because developers did not observe the rule of incremental enhancement:

Any web site should provide a basic bottom layer of manipulable text which may be enhanced by other features

Many Java features are now accessible but one piece of poor coding can disable the accessibility of a whole site.

d) Refreshable/Scrolling Text

I can illustrate this problem best by describing the proud re-launch of an accessible 10 Downing Street web site. The home page contained a scrolling news feature which meant that the screen reader could not 'grab' the accessible text before the page was completely refreshed to facilitate the scrolling.

e) Inconsistent Command Routines

Web page layout owes a huge amount to the conventions of setting movable type this is the primary reason for the use of boxes. Microsoft products use a variety of buttons to select one or more options in a box. The ways of getting into and out of these boxes are not consistent. VIPs frequently find themselves in recursive loops.

2.7 WCAG Compliance

At its publication in 2001 the WAI Web Content Accessibility Guidelines [vi] were an instant political success. They were adopted as elements of legislation and regulation by almost all of the major developed economies. Sadly, however, those who legislated were the chief infractors. It is impossible to provide a clear figure of web accessibility compliance because of problems with defining what compliance is; for example, a web site can pass an automated test for WCAG compliance but still not facilitate task completion. The compliance was always defined in terms of the coding not the outcome. However, although estimates vary, no government has ever made more than 30% of its pages accessible. Without a strong lead, major corporates have been slow to follow and SMEs have been proportionately worse still. Low accessibility and the cost of assistive technology are symbiotically detrimental. WCAG 2.0 [vii] has just been published and has been greeted with great acclaim but I suspect in spite of its superiority over WCAG 1.0 that compliance will continue to decline in proportionate, if not absolute, terms.

2.8 PDF

As I speak, the most recent problem with text accessibility is the increasing use of PDF. The primary purpose of PDF is to preserve document integrity and, therefore, to stop text manipulation; this runs exactly counter to the need for text to be manipulable so that it can be alternatively rendered. Work is going on to provide 'fixes' for this situation but it is a typical example of a disregard for accessibility; governments that have enacted legislation on web access routinely use PDF as their standard house format. it is possible to use tools such as Acrobat Reader to extract manipulable text from a PDF but with a screen reader you never know how much of the content you have managed to 'grab''.

2.9 DAISY

Turning from the relatively chaotic world of the Web to the calm of the library, the shift from analogue tape to digital media held out the promise of a new experience in reading. In May 1996 the DAISY (Digital Information Accessible System) Consortium [viii] was established to agree a global standard for tagging books in recorded audio so that they could be navigated by VIPs. The Consortium was made up of alternative format text publishers and so the task here was to export the standard to generic providers. As I speak, final discussions are taking place to integrate DAISY with ePub, the leading generic standard for eBooks. The problem, to which I will return in a moment, is that DAISY operates within a 'closed' system, i.e. specially prepared digital text is accessed on special players, another example of a 'tax' on the VI sector. Nonetheless, in addition to making novel reading much simpler, DAISY means that books such as cookery books can be navigated simply and effectively.

2.10 OCR

From the dawn of the digital age the holy grail for alternative format publishers was to obtain the file of a book from the generic publisher. There have been, however, two barriers:

Production Methods;
Copyright.

a) Production Methods. An author may present his initial manuscript in a manipulable format such as Word, but once his editor and publisher take over, the process moves to other applications such as pdf or quark. Even if you can obtain a final book version in a digital format it cannot be alternatively rendered without removing all the metadata and other printer's 'flags'. Waiting for this "Holy Grail" of the publisher file has greatly retarded more promising developments.

The most obvious alternative to the publisher file is the use of OCR to take text from the page and make it digital. This technique has developed but there are still very few macros for lifting metadata. Macros can be written to call the editor's attention to any string of text preceded or succeeded by significant white space. For example, if a piece of body text finishes half way down the verso and text larger than body text is displayed half way down the recto, the chances are that a new chapter or section is beginning. Metadata has to be 'lifted' because translating into braille or producing larger or smaller print than appears on the page requires re-pagination. This, in turn, requires re-editing the index. This may sound more complex than using the 'dirty' publisher file but for most plain text the opposite is true.

2.11 Braille Code

One sideline of which we need to be aware is the nature of braille.

Braille code consists of combinations of dots within a cell (column) three dots deep and two wide. This allows for a combination of symbols

2⁶ - 1 = 63

26 of these characters are used for the alphabet and some other ten for punctuation. Numerals are usually the first ten letters of the alphabet with a numeric prefix.

However, as analogue braille had to be produced by mechanical devices to make single copies or metal plates, contracted forms of braille were developed with tables of rules for the use of symbols such that:

Dots 2 5 6 represent:

The letter group ‘dis' at the beginning of a string;
The letter group ‘dd' in the middle of a string;
A ‘full stop' at the end of a string.

Thus, symbols and combinations of symbols cannot be translated on a character for character basis from print to braille or vice versa. This use of tables has restricted braille translation to specialists. Although the coding is now straightforward, layout rules are still somewhat primitive.

2.12 Copyright & DRM

Not uncommonly in development, it is the human factor rather than the failure of technologies which has caused the greatest problems. We have already seen how the restrictive outlook of Microsoft has severely limited the integration of accessibility into generic products and this theme will be developed in later sections but at this point I want to note the pervasive barrier of copyright and digital rights management.

Copyright is one of those areas where my 'plane crash theory' applies, i.e., at least three things have to go wrong before there is a disaster. In terms of rights of access by VIPs to copyright material, here are the four factors:

Analogue copyright was sought as charitable;
Specialist publishers produced closed system audio players;
Rights holders irrationally fear piracy;
Business has successfully lobbied for status quo.

a) Analogue Copyright.

In the analogue age specialist publishers sought permission to produce and lend braille books free of charge as an act of kindness by authors and publishers. This was usually granted but the law until recently stated that the rights holder needed specifically to consent; rights holders who did not answer letters therefore de jure withheld permission.

b) Closed Audio Systems.

When audio books were first produced, rights holders demanded that recordings for VIPs should be played on closed systems. Libraries for the blind therefore produced special closed system audio book players.

c) Fear of Piracy

Although there is evidence of music piracy (Autolychus in Shakespeare's A Winter's Tale was surely selling illegal ballad sheets) there is little evidence, outside pornographic works, of text piracy and no known case of a VIP being prosecuted for text piracy. In any case, a VIP would, necessarily, be less efficient at piracy than any number of illegal off-shore operations. It was only in 2002 [ix] that the UK granted automatic copyright permission for books to be put into braille and even with closed audio systems copyright permission is a grey area. Where blanket permissions have been granted these are usually territorial and this has blocked the establishment of a global library of alternative formats.

3. Telephony

The story of accessible telephony for VIPs is a simple case of the law of unintended consequences. In 1999 the RTTE [x] (Radio and Telecommunications Terminal Equipment) Directive of the EU (1999/5/EC) said that except for health and safety purposes, no regulations should be promulgated with respect to the design of telephone equipment. At once this wrecked the vocational opportunity for blind telephone operators but it also meant that handset manufacturers were not required to make their equipment accessible. Again, the assistive technology sector was called upon to develop software to provide audio feedback on dialling and to make menus, SMS and email accessible. Conversely, the simple device of providing an identifying feature on the number five was an instant and low cost success.

4. Television

4.1 From its inception, television has been heavily regulated. The initial reason for this was, of course, that it could be and politicians were naturally wary of an unregulated medium which reached into every home.

In the United Kingdom, the concept of public service broadcasting, exemplified first by the BBC but later by the obligations on ITV, was realised through the granting of spectrum in exchange for certain content requirements. In the 1980s these content requirements were supplemented by accessibility requirements, first for sub titles for deaf people and later by requirements for audio description which supplies additional descriptive text to aid comprehension. The 2003 Communications Act stipulated that all major channels should broadcast at least 10% of a broad range of programming with audio description. But whereas in the supposedly free market USA there was legislation to require an on/off toggle to access these special services, no such rule was made in the more dirigiste European Union which led to a series of 'fixes'. Most major broadcasters are now well on their way to full compliance, some have exceeded the requirement and there is a move to raise the mandated level of audio description to 20%.

However, although the switch from analogue to digital television has lowered the cost of special services such as subtitling and audio description, VIPs now face another hurdle in the shape of broadcasting metadata and menus. Electronic Programme Guides (EPGs) are not subject to accessibility regulation and it has proved difficult to persuade manufacturers of television sets and set top boxes to incorporate 'talking' metadata and menus. RNIB has now developed exemplars.

5. Technology and the Elderly

I now want to say just a few words about ICT and elderly VIPs, noting that this is the subject of a separate lecture given here last year [xi].

One of the characteristics of many analogue technologies is that they are not plastic. Admittedly, we can alter the volume and contrast on an analogue television but many technologies are not susceptible to adjustment:

Print in books cannot be adjusted but only subject to magnifiers;
Independent mobility is learned in the presence of an instructor.

a) Text/Graphics Plasticity.

In the analogue age a person going blind invariably reached a cut-off point, being required to switch from, say, modified print to audio and/or braille; but in the digital environment she can use all three simultaneously, gradually shifting emphasis from the visual to the auditory and tactile. This makes the process far less traumatic. Likewise, the visual world can be interpreted so that the eyes that no longer see the intricacies of plaster work on a ceiling can be shown the same phenomenon on a screen.

b) Out or In.

In the analogue age, a blind person learning to become independently mobile was accompanied by an instructor or had to stay at home. In the digital age, a learner can use outside broadcasting technology and location-based services to make contact with a remote carer who can provide assistance.

In both of these cases there is no sharp disjuncture between the different phenomena which means that a person has much more flexibility.

[iii] Web Accessibility Initiative http://www.w3.org/WAI/

[iv] BBC Homepage http://www.bbc.co.uk/

[v] Carey, K. and Stringer, R. (2000) The Power of Nine Library and Information Commission Research Report 74. ISBN 1-902394-46-1 - ISSN 1466-2949 & 1470-9007

[vi] World Wide Web Consortium: Quick Tips to make Accessible Web Sites from: Web Accessibility Initiative (WAI): Web Content Accessibility Guidelines WCAG (Version 1.0, 2001, http://www.w3.org/WAI

[vii] WCAG 2.0 http://www.w3.org/TR/WCAG20/

[viii] DAISY Consortium http://www.daisy.org/

[ix] Copyright (Visually Impaired Persons) Act 2002 http://www.rnib.org.uk/xpedio/groups/public/documents/PublicWebsite/public_CVIPsAct2002.hcsp

[x] Radio and Telecommunications Terminal Equipment (R&TTE) http://ec.europa.eu/enterprise/rtte/dir99-5.htm

[xi] York Workshop Sept 2008 http://www.humanity.org.uk/articles/accessibility-general/ability-technology-sight-deteriorates