Back To Basics: How Poor Usability Effects Accessibility

In recent user testing with a range of participants including Visually Impaired (VIP) and Blind users we found that the majority of problems were common across all groups. However the effect of poor usability is more severe for users with visual disabilities. Surprisingly all of the issues are very familiar and are easy to fix so we thought we’d revisit some of the basics of accessible web design.

Information Retrieval Behaviour? – “and now for the science bit”

All users explore a webpage in a similar manner. Attention is focused on the headings and links on a page. However there are differences. People using screen readers can extract all the headings or links on a page into a single list and then read down through them. This of course means that they do not receive any of the supporting information such as graphics, the prominence given to an item or the accompanying text associated with a heading or link which a sighted user will quickly scan to gain more information about a heading or link. It is therefore extremely important that headings and links are implemented correctly if a webpage is to be accessible.

When users are looking for specific information they often try the site search function after a brief scan of the available options. VIP and Blind users are generally more likely to try searching as they have more difficulty scanning through text content.

Make Headings and Links Self Explanatory

As the only information a screen reader user will receive on a heading or link is the name of that item, it is essential that the name is completely self explanatory and does not require additional information to make sense of it. It is also vital the language used is plain and understandable and uses familiar terminology. Failure to do this means that certain users will not be able to gain access to information on the website.

Format Headings Correctly

Screen readers rely on the correct use of the HTML heading mark-up differentiate headings from the surrounding text. It is essential that the headings are marked-up correctly rather than formatted using bold text and a larger in font size.

Have an effective Search

Because VIP and Blind users rely more on the search function than sighted users it is essential to have an effective search. The results returned from a search must be relevant and text of the results must clearly describe the target page. It is also very important that information on the number of results obtained and the number shown on the page is provided to the user.

Summary

Clear descriptive language and correct use HTML mark-up are STILL the key factors in real world website accessibility and usability.