Impact on users
The following is an overview of common form accessibility errors and the impact on users with a disability.
- Non-text content which has no text equivalent
When text alternatives are not provided for non-text content, information cannot be rendered by assistive technologies into other forms that people may need, such as large print, braille, speech, simpler language or custom colour combinations.
- Information and structure which can’t be programmatically determined
When form elements are used in a way that does not match the semantic meaning, the information, structure and relationship of content may be lost when the presentation format changes. Assistive technologies and user agents may not be able to accurately interpret information and correctly adapt the presentation to a visual, auditory, or tactile format.
- A meaningful sequence is not maintained
The visual reading order of form content should be presented in a meaningful and logical sequence i.e. left to right and top to bottom. Screen readers will read form labels and components in the order that it appears in the source mark-up. When meaningful sequence is not maintained, form content may be displayed incorrectly when presented in alternative formats by assistive technologies.
- Instructions that rely on sensory characteristics
When ASCII characters are used instead of text, users of screen readers may not be able to understand the meaning of the content. Some ASCII characters are ignored by the screen reader which means information is omitted completely.
- The form is not keyboard operable
When a keyboard user encounters a keyboard trap they are unable to exit a site feature or content area and are effectively stuck. They must close the browser window and start again. If all content, controls and interactive elements cannot be operated via the keyboard, users that rely on the keyboard alone will be unable to navigate, understand and complete the form.
- A logical focus order is not maintained
When the keyboard focus order of a web page is altered, the focus may no longer be consistent with the visual reading order. Users who rely on the keyboard to navigate and browse content, such as those with mobility impairments, reading difficulties and visual impairments, may find the tabbing focus sequence confusing, or be unable to find the keyboard focus at all.
- Mechanisms to help people find information are not provided
People rely on mechanisms to find information that are most suited to their needs. On a large website, if a search is not provided, blind users may find it cumbersome to tab through a large navigation block, or visually impaired users may find it difficult and confusing when doing the same with a screen magnifier or screen reader. Providing a search benefits everyone by allowing information to found quicker.
- An unexpected change of context or content occurs
Navigating a document or inputting data into a form should be a predictable experience for all users. People with visual and cognitive disabilities and motor impairments may become disoriented if changes in context or content occur unexpectedly, such as a new window popping up or the focus being moved to another form component. The user may be not aware that a change has occurred as a result of their actions if they were not adequately informed or did not initiate the change.
- Components are not identified consistency
Functionality that is similar or used more than once on a website should be labelled consistently to create familiarity and ease of use. This improves a user’s ability to find information or use similar functionality on other pages without having to relearn how.
- Errors are not identified and described in text
When an error is detected it should be identified in text and described in detail. Without specific information about the error, screen reader users may believe a form is not functioning and may abandon it altogether. Errors that are identified with colour alone, or symbols or icons, may not be understood or recognised by users who are blind or colour blind. This may also be the same for users with learning or language difficulties, or other cognitive impairments.
- Labels or instructions are not provided
When content requires user input, labels or instructions should be provided to assist the user with completing their task, and to minimise mistakes made:
- If labels and instructions are not provided and associated with a form input, a blind user will not know what information to enter.
- Similarly, labels and instructions that are not visually located closely to a form input can prevent users of screen magnifiers from seeing this information.
- Labels and instructions that do not give examples of expected user input can reduce the likelihood of users with cognitive, language and learning disabilities entering the correct information.
- Keyboard users may submit incomplete forms if required fields are not labelled; trying to find the incomplete input is a tiresome task when information is not provided to assist.
- Error suggestions are not provided
When error messages are provided, they should include suggestions on how to correct mistakes, such as examples of the correct user input. Without suggestions, people with visual or motor impairments, or cognitive, language and learning difficulties may not understand what the required input is and may not be able to correct their mistakes. After repeatedly trying to input the correct information, which can be very tiresome; users may ultimately abandon the form altogether.
- People are prevented from making serious errors
When a form is used to initiate a legal or financial commitment, or to modify or delete user data, a step to reverse, check or confirm the user input before submitting the form should be provided to prevent users from making a serious mistake. Users with visual or cognitive, language and learning difficulties may have input incorrect characters, or users with a motor impairment may have hit incorrect keys.