We recommend that before you start work on what may become web content, you read the universal accessibility guidelines or at least the techniques used to deploy them.
Some content cannot be made accessible. In such cases, it is sensible to provide the same information in an alternative format but it is important that this information is maintained along with the comparable content. Notification of what media type is provided should also be given.
Computer browsers provide users with a range of choices about privacy, security, language, content and more when they request a webpage. The information required by the browser to make sense of these choices is usually stored in the (hidden) header of the incoming webpage. This information about the information on the webpage is known as metadata.
In some cases, potential users of a website will not be able to gain access to the website simply because it does not convey the right information to make it accessible.
Many work environments and educational institutions, and many homes, filter out information which is not described at all or is described but not as within their acceptance levels. Such material is often not included in the indexed catalogues of the search sites either.
One of the ways in which browsers can assist users is to differentiate between different parts of a webpage by association with the structured elements of the page. For instance, knowing that something in large font is a heading rather than just being emphasised makes it possible for a browser to work down through text by headings. This process, automatic to those looking at text and detecting cues, need not be lost to users dependent upon screen readers. All that is required is that the content is structured. One simple way to do this is to work with style sheets, perhaps starting writing any document with a style sheet connected to an outliner program. Expert users of word processors such as MS Word will be familiar with this approach. It is highly recommended to all others.
Most browsers are set up to limit the language of the webpage content. This often has to do with the capabilities for presentation of the characters, among other things. Where the language of a webpage includes several languages, this needs to be notified.
Tables of information can be presented in web pages but tables should be used only for tabular kind of information. This information should be well marked up so that it reads easily when not presented visually.
An example might help:
|Name||Cups||Type of Coffee||Sugar?|
which can be rendered as follows by a screen reader:
Caption: Cups of coffee consumed by each senator
Summary: This table charts the number of cups of coffee consumed by each senator, the type of coffee (decaf or regular), and whether taken with sugar.
Name: T. Sexton, Cups: 10, Type: Espresso, Sugar: No
Name: J. Dinnen, Cups: 5, Type: Decaf, Sugar: Yes
Unfortunately, this way of making tables only came in with HTML 4.0 so we recommend starting to use it but sadly the benefit might not be available for all immediately.
There are times when video and images offer the best form of expression. In such cases, there is no need to do more than have a 'degradation' path for the object.
For example, a video clip might show some people having a picnic. A single image might be provided for those who cannot run video. An alt tag, to be displayed in cases when the image or video is not being seen, might explain that what is not being seen is a video or image of a picnic scene. Such a description alerts the user to the fact that the image serves the role of illustration but it does not help someone who wants to know what is in the picture. A long description solves this problem - explaining that there is blue sky, grass, four people sitting around a rug, ... Such a description can be made available to users and the convention of placing a 'D' after the object icon, indicating that there is such a long description, is all that is required. The 'D' needs to be linked to the description, of course.
HTML 4.1 offers neat ways of including all forms of expression about objects but at the time of writing, not many browsers are yet set up to make use of the options. The downward compatibility of HTML 4.1 caters for this too.
It goes without saying, or does it, that image maps are very difficult to make accessible. Where possible, other ways of providing navigation information should be included in the content.
The range of web standard formats is increasing. before using a proprietary solution, we recommend trying to find a standard solution. This way, more poeple will have access to the material.
One common way to provide material on the web, especially material which has previously been published, is as 'pdf' files. As the Access! page of the Adobe Website states:
"Portable Document Format (PDF) is a platform-independent means of exchanging visually rich documents. PDF is fast becoming a pervasive means of communicating richly formatted information on electronic networks including the Internet and its most popular segment, the World Wide Web (WWW). PDF documents are rich in visual layout, and are popular among users capable of appreciating the high-fidelity visual presentation. However, visually impaired users have found PDF documents hard to access. Conventional screen reading technologies ---software that enables a visually impaired user listen to the contents of a computer display--- prove ineffective when reading the rich visual presentation. "
Using PDF files is not considered helpful to users in a number of situations but the good news is that now they can be 'opened up'. See the full text of the note from T.V.Ramin.
Most screen readers, for a start, are not Java savvy. Many low-end computers which people use to browse the web are similar. Alternatives should be provided where these perform functions - eg, if a form can replace an applet, it should!
Copyright Liddy Nevile 19 March 2001. This material may be copied if source is acknowledged.