Web Accessibility

Release: 2008-01-27
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Accessibility of the webpage

 The baseline of webpage accessibility is every non-text object such as an image, image button, video, audio, scripting, Flash, Java Applet and ActivX Control that provides important information for the user must have text alternatives.

This includes all images and image buttons must have an alt attribute. If the image is just for decoration then the alt attribute can be empty but there must be an alt attribute present as it is a required attribute in HTML and XHTML. If there is text within the image then that text must be in the alt attribute or next to the image (in the case of an image caption or the image is an icon for a navigation link).

All links must have descriptive text. So if you just have 'click here' for them and read the links (as screen reader software do, to inform visually impaired or blind users of the document outline: headings and links) then it does not tell you where the link is going. Text like 'Download Holiday 2007 brochure PDF' and 'Top story: Human Kind finally upgrades to money-less civilisation!' are examples of descriptive link text.

Form controls like text fields, drop-down and list selects, radio and checkboxes must have id attributes and a label element that bind to the form control's id attribute. As checkboxes and radio buttons may be too small for some users to see, binding labels and form controls allow the web browser to understand the explicit connection between the item and its label. On some operating systems this will allow people to click, or tab to and press enter for, the text label and the web browser will tick or untick the checkbox or select the radio option. Also clicking the label of a text box would shift the focus to the text box and be ready for text input.
Screen Readers will also confidently read out the text label explicitly associated with the text box or other form control.

Any non-live presentations such as video and / or audio must at least have a transcript for those who can't hear what is going on so they can read the text alternative. Captions or text that explains what is happening for those who can't see what is happening in a video should be synchronised with the scenes.

Colour contrast is a must for anyone let alone those with visual impairment or dyslexia. Never convey information with colour alone as most of the population do suffer from at least one of the many colour-blind disabilities.

There is a W3C Web Content Accessibility Guidelines (WCAG) 1.0 standard with a checklist at http://www.w3.org/TR/WCAG10/full-checklist.html but some accessibility checkpoints are actually outdated and irrelevant in this day and age as web browsers and screen readers have imporved since 1999 when the standard was published.

Don't put pre-stated text in text fields as to some one without sight this is indistiguishable from the label of the text field.

Do not use accesskeys as this will interfere with screen reader shortcut keys.

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