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The Accessibility of the World Wide WEB for visually impaired people

Sylvie Duchateau(1), Dominique Archambault(1,2) and Dominique Burger(1)

(1)INSERM U483

Université Pierre et Marie Curie B23

9, quai Saint Bernard

75252 Paris cedex 05

France

(2)Université du Havre

Dépt. Information Communication

IUT du Havre — BP 4006

76610 Le Havre

France

Sylvie.Duchateau@snv.jussieu.fr
Dominique.Archambault@iut.univ-lehavre.fr
Dominique.Burger@snv.jussieu.fr

Keywords: accessibility, visually impaired, Web.

Abstract

This paper reports on a study about the accessibility of Web sites for visually impaired people. It shows that the evolution of the Internet as a more and more graphical environment causes problems of accessibility for people who access the Web through specific tools like Braille displays speech synthesisers or magnifying. Some of the most frequent problems encountered by blind and partially sighted users are explained and some solutions to reduce the problems of accessibility are proposed. At last, the paper draws a list of the actions which have been started in France in order to inform those who make Web sites about the situation for visually handicapped.

Introduction

The Internet was initially created to allow an information exchange between scientists. For that reason it was principally based on textual information. However, since Internet has become a communication media for everybody, since it is more and more used for commercial purposes and more and more people who don't know much about computer use it, the Internet is becoming more and more graphical. These changes don't bring advantages to everybody. They are a source of difficulties for those who cannot access the Internet by the means of a screen, especially blind and partially sighted users (who have to use a screen reader to get to the screen information) and people who access the Internet via a telephone or from their car.

The evolution of Internet has lead to the creation of a world wide initiative (WAI) which formulated recommendations to make the Internet more accessible. In France the Web Accessibility Initiative [2] is represented by the INRIA and the INSERM in co-operation with the BrailleNet association [1]. BrailleNet decided to participate in the WAI since BrailleNet's objective is to help visually impaired have an access to education through the Internet. An information campaign has been set up to inform the opinion, the webmasters and the policy makers about the accessibility problems encountered by people with a visual impairment. This information campaign explains how the Blind and Partially Sighted can use Internet and shows how the WAI recommendations will facilitate the Internet access for these persons.

A study on the accessibility of more than hundred sites was realised to find out which problems visually impaired are most frequently confronted with and to find solutions that should be submitted to the authors of Web pages.

First we'll explain how the study was conducted, and which method was used. Then, the results of the study will be presented, with proposals for the improvement of accessibility.

The method

The Internet provides so many sites that it is impossible to gather an exhaustive list of them. Consequently, the number of sites was limited to 111. The sites belonged to categories that can be of interest for French blind and visually impaired users. Those categories are: French newspapers, radio and television channels, national and international institutions (like the UN, the French parliament, the European Union etc.), sites of the administration, public services (like libraries,), specific sites for handicapped people, sites about computers or Internet, leisure (about the cinema, television, music groups and so on...) sites for students or universities, services (post office, airlines, railway company...).

To check the accessibility of these Web sites two browsing methods were used. The first one was a so-called "specific browser", BrailleSurf [5], developed by the INSERM, which combines speech and Braille display and can be used by a range of speech synthesisers and Braille displays. The goal of this browser is only the access to Internet.

The second tool was the use of a non specific browser, Internet Explorer 3, with a screen reader, called DraculaNet and a Braille display with a length of 20 characters. To complete the results, several blind people were asked about their experience with their specific browser or their Windows access software.

The most frequent accessibility problems

The study showed some accessibility problems as the most frequently encountered. The use of different access tools showed that these problems can totally differ from one browsing solution to the other, but that many of them are similar for any blind user (note that the WAI User Agent working group provides recommendations for browser developers so that these differences may disappear [2]).

These problems can be classified in two categories: technical problems and conceptual problems. Some of the technical problems should be solved by the developers of specific browsers or specific screen readers. However, a certain number of them must be taken into account by the Web designers. In many cases, page authors just have to add a few HTML attributes or elements.

Conceptual problems are more complex to solve. But bad structured sites are not only disturbing for visually impaired people but also for sighted people.

Technical problems

A frequent problem is when the text of the link does not give explicit information about the document it points out. Indeed, the browsing tools used by visually impaired people often allow to jump from link to link. Even if a blind user reads the whole text he cannot automatically recognise the meaning of a link since the site layout cannot provide useful information.

This problem is the most important, especially when the images are used as a link or a heading. Consequently, it is very important to write an appropriate comment for images. This comment should describe the function of the image and not what the image looks like. If the image is used as a link, the comment should be the text of an equivalent textual link. If the image contains a text standing for a heading, the comment must include the exact heading text.

In order to provide full accessibility, the use of too many images should be avoided for the headings. In many cases the characteristics of the font can be defined precisely using cascading style sheets (family, size, style, colours...), and even downloaded fonts can be used!

Image maps are often an obstacle to accessibility. As graphical elements they are sometimes ignored by some browsers. The old server-side images map cannot be accessible, fortunately they are less and less used.

In the case of client-side image maps, specific browsers or screen readers are able to display a list of links corresponding to the different areas. For each link, the content of the "ALT" attribute is displayed. But if the "ALT" attribute is missing, the name of the HTML file will be used (it is often the same file name, from different directories, but the directories are not displayed, and only a list of links like index, index, index is shown by the browser). Consequently, the best way to make an image map more or less accessible is to comment each <AREA> element of the map with the "ALT" attribute.

For full accessibility, the use of image maps should be avoided.

As far as frames are concerned, browsers can be classified in two categories: some browsers allow to swap from one link to another. It is usually the case when standard browsers are used with screen readers. The browser loads the content of each frame and the screen reader displays the <TITLE> element as a label for each frame. On the contrary, specific browsers show a list of links pointing at the different documents located in the frames. The documents are not loaded automatically, the specific browser only uses the "name" attribute as the text of the links.

As a consequence the names of the different frames must be explicit. If the frames are called "frame1", "frame2"... the user has to click on each of them to know what is inside the frame.

The second category of browsers only displays the content of the NOFRAME element. If this element only contains a message like "Sorry, this is a multi-frame document, you should use another browser", the user will not be able to enter the site. The fastest way to reach a first level of accessibility is to provide in the NOFRAME element a list of links to the different documents displayed in the frameset (in a way, doing like the browsers described above).

A site is completely accessible, when an alternative document, providing the full information of the site is available, but in this case, the alternative document should be updated as frequently as the multi-frame one. If it is not possible to update the alternative document, the first solution should be chosen.

Scripts cannot be displayed by all browsers. In some cases scripts have no incidence. For example if a script is used to change the aspect of an image (commented by a proper "ALT" attribute) when the mouse points at it.

However, the site designers should ensure that whole information can be accessible without scripts or applets. In some cases the applet just has to be commented. The <NOSCRIPT> element can also be used together with the <SCRIPT> element.

When an applet is necessary to understand the document, this applet must be accessible (see the Java Accessibility Page [6]).

Tables cause often some trouble to visually impaired users. According to the browsing solution the results can be totally different. Screen readers generally display on a single Braille line the line that can be seen on the screen. As a result, the blind user reads one line of each column of the table or of the multi-column texts. This text does not make any sense for him. So it is rather difficult to identify where each column stops.

Specific browsers, on the contrary, display each cell of a table separately, line after line. Interdependent text portions should not be divided into several cells (the text should be understandable without taking into account the HTML table formatting elements like "TABLE", "TR", "TD").

This solution seems to be more satisfactory since the text remains understandable if this simple condition is followed.

For a full accessibility, the use of tables should be avoided, especially when they are used for the page layout. In this case style sheets provide much more possibilities.

Conceptual problems

Conceptual problems are linked to the way the site has been organised and for which people it is made. The best way to make an accessible site is to think about the way users will access it. It concerns visually impaired users, but also people with hearing disabilities, with cognitive problems, or people who cannot use a pointing system like a mouse. On the other hand, not only disabled persons may be disturbed by bad structured sites: children or people who are not familiar with the Internet, people who have a slow access (and even with fast access, the network is often overflowed).

In many cases, the accessibility tips concerning links, images, image maps, frames, tables... are taken into account but the site itself is not really accessible because of its organisation.

Some sites use multiple frame sets. So when a user selects a link, the frameset changes into another, and so on. Then even if the frames are correctly named it will be very difficult for a visually impaired user get to the information. In this case, a lot of sighted users will be disturbed.

If a site uses frames, the frameset should be the same for the whole site.

Some sites have a complex structure, for different reasons: for example they may contain a lot of information. The structure should appear clearly when the user enters the site, or in a secondary document. It should be clear enough to be easily memorised by the user.

The homepage is the first document the user sees, but it is often a cause of inaccessibility. It represents the window of the site, of the organisation to which it belongs. Therefore, the webmasters try to make it attractive with nice design, images and animated events. This is not necessarily a problem for accessibility. In that case a way is to provide somewhere in the document a list of textual links, or even images with appropriate comments. But the best way is to provide an alternative page with the same links.

This page will be used by visually impaired, but also by users who are in a hurry. When one finds out a new shop, the first time he looks at the window, but then, if he is in a hurry he will directly go into the shop.

More and more sites are optimised for Netscape Navigator or Microsoft Internet Explorer (last versions). A user who works with another browser will not access the same information, or not even be able to enter the site! Even if 90% people use one of these main browsers, the 10% others still represent a lot of people. Some people may refuse to use them, and they are in their right. But other cannot use them, especially visually impaired people. A message like "You should download this browser, click here" is not useful for someone who cannot use it!

On the other hand it is not good for anybody if only two browsers exist.

Conclusion

This study on the accessibility of Web sites helped to highlight a certain number of difficulties which could easily be overcome. It showed that it is urgent to conduct the consciousness raising campaign by the authors of Web sites to inform them about the problems visually impaired users are confronted with. Even if some improvements could be achieved by the specific browsers and by the screen readers, some other accessibility problems can only be solved by the Web sites designers themselves.

In France we has started several information actions:

This information is also dispatched by the newspapers and the television channels, and the organisation of conferences (a conference was organised in the "Cité des Sciences" in "La Villette" on the topic of Internet implications for visually impaired people).

Since the information campaign has just begun its effects are not important when this text is written. However, we already received answers from some Web designers. The most positive answers were a need to meet us and to think together over what could be done to improve the site accessibility. Other responses showed an interest for the information and the site designers promised to try to change the structure of their site.

Unfortunately, many people answered, those problems would concern a minority of internet users. They would have optimised their site for the two main browsers that are actually used and it would be too much work to adapt their sites to other browsers.

As those answers show, there is still much to do to guarantee a full accessibility of the Internet for visually impaired. Nevertheless one can hope that in some months the behaviour of Web site designers may change, if they see that improvement was accomplished by other sites.

References

[1] BrailleNet — http://www.braillenet.jussieu.fr

[2] WAI, Web Accessibility Initiative — http://www.w3.org/wai

[3] Fiches accessibilité, BrailleNet, 1999 — http://www.braillenet.jussieu.fr/fiches

[4] Better access to the WEB for blind and partially sighted people, D. Archambault & D. Burger & S. Duchateau, BrailleNet, 1998 — http://www.braillenet.jussieu.fr/livreblanc/english

[5] BrailleSurf, An Internet browser for visually handicapped users: principles and methods, D. Hadjadj & D. Burger, 15th IFIP conference, Vienna/Budapest, 1998

[6] Java Accessibility Page — http://trace.wisc.edu/world/java/java.htm

[7] "Les enjeux d'Internet pour les personnes handicapées visuelles", BrailleNet & Cité des Sciences et de l'Industrie de la Villette, Paris, February 9 1999