Impact on users

The following is an overview of common source order accessibility errors and the impact on users with a disability.

Providing accessible navigation
If the visual or keyboard order of the navigation does not follow the source order then a screen reader could end up reading navigation items in an incorrect order or not at all.
Provide a natural keyboard focus order
When a keyboard focus order is imposed that overrides the natural keyboard order of the webpage in line with the source code the end user can miss items or be taken around the page in a counter-intuitive manner.
Content is presented in a meaningful manner

The visual reading order of content (including tables and forms) should be presented in a meaningful and logical sequence i.e. left to right and top to bottom. Screen readers will read the content of web pages in the order that it appears in the source mark-up.

When the visual order and source order do not match, relationships within the content may not make sense to a visual user and may also be read incorrectly by a screen reader.

Avoid changes in context or content

Changes in context or content that occur unexpectedly i.e. not at the user’s request, can cause disorientation for the end user, resulting in losing track of their current position in a website or taking them to a different page entirely.

If small changes in content such as a change in form dropdown content appear prior to the current focus the end user may not be aware that the change has taken place.

Use the appropriate mark-up or CSS to manipulate and present information
The meaning of content e.g. table data, may not be conveyed accurately and could be misinterpreted by an assistive technology user if whitespace is used for formatting in place of the appropriate code or CSS.