The local government Society of IT Management (Socitm) this week published a report on website accessibility which included a round-up of the five most common accessibility errors.
The society estimates that these five errors account for 76% of all website accessibility failures, and it asked Robin Christopherson, Head of Accessibility Services at the charity AbilityNet, to describe their impact. Robin is blind and uses the popular ‘JAWS’ screen reader software to access the web.
An edited version of Robin’s assessment follows.
“Common failure 1 is to have no alternative text for images.
“This is an extremely common occurrence. I visit a website and am confronted with numerous unlabelled images. For mouse users this ‘alternative text’ is what pops up when you hover over the image. The average web page has dozens of images, from photos and adverts to ‘eye-candy’ such as spacing graphics and design flourishes. Many of these images are also clickable links or buttons, and not knowing what these are makes navigation impossible. Imagine trying to drive from A to B where the signposts at every roundabout or junction are blank. A disaster!
“Every single image on a website should be properly labelled. You don’t need to begin captions by saying “Picture of.”, as I already know it’s a picture. You don’t need to label ‘spacer’ or ‘eye-candy’ images (but give these a default caption so that the page still passes the accessibility checkers) and, above all, make sure that all images that are also links or buttons describe what will happen when you click on them, eg alternative text as “Marilyn Monroe – click to read her life story”.
“As well as revolutionising the site for blind users, labelled images will also help those with dyslexia and literacy difficulties who use text to speech software (they hover their mouse over any text or image and the content is spoken out). It will also help those with images turned off (many hand-held users do not display images) and, last but by no means least, Google loves labelled images.
“Common failures 3 and 4 are errors in simple and complex data tables.
“Thankfully, these days most websites use style sheets rather than tables to style and arrange the blocks of content on a web page. Where data tables are concerned, however, it is still the case that most are not coded in such a way that the relevant headings are spoken by a screen reader when moving from cell to cell. I hear ‘1327’ and ‘1727’ with no idea of whether these are sales of widgets or notable dates in history.
“The solution is to make sure that all headings of columns and rows are coded using the ‘th’ tag instead of the ‘td’ tag. A screen reader will then announce these along with the contents of the cell, putting the data in context (eg “Widgets sold in June, 1327″).
“And finally, common failure 5 is the use of features with a lack of accessible alternatives.
“Here you are confronted with an inaccessible bit of content or function and you search for a way around the obstacle, but to no avail. A classic example is ‘CAPTCHA’. A CAPTCHA is a type of security test used to determine whether the user is human (and so exclude automated spamming programmes). A common type of CAPTCHA requires that the user type the letters of a distorted image. Since the image is by definition unlabelled (as otherwise it can be read by malicious software) an alternative (such as an option to register by phone or email) is essential.
“When it becomes clear that you have content or function that cannot be made accessible, offer an accessible alternative. For example, the Google accounts sign-up process that uses CAPTCHA also has a link to an audio version of the code to be entered plus a link to contact customer services for those who cannot access either the visual or the auditory option.
“Always remember that an accessible site is a popular site – and not just for the disabled community. Research has shown that a site that is designed with accessibility in mind is also easier to use by all.”
NOTE: ‘A world denied: a supplement for Better connected 2008 on website accessibility’ is available from Socitm. It is free to subscribers to the society’s Insight programme; £50 for non-subscribers in the public and voluntary sectors and £99 for private sector non-subscribers.