Understanding Timing Adjustable

Intent of Timing Adjustable

The intent of this Success Criterion is to ensure that users with disabilities are given adequate time to interact with Web content whenever possible. People with disabilities such as blindness, low vision, dexterity impairments, and cognitive limitations may require more time to read content or to perform functions such as filling out on-line forms. If Web functions are time-dependent, it will be difficult for some users to perform the required action before a time limit occurs. This may render the service inaccessible to them. Designing functions that are not time-dependent will help people with disabilities succeed at completing these functions. Providing options to disable time limits, customize the length of time limits, or request more time before a time limit occurs helps those users who require more time than expected to successfully complete tasks. These options are listed in the order that will be most helpful for the user. Disabling time limits is better than customizing the length of time limits, which is better than requesting more time before a time limit occurs.

Any process that happens without user initiation after a set time or on a periodic basis is a time limit. This includes partial or full updates of content (for example, page refresh), changes to content, or the expiration of a window of opportunity for a user to react to a request for input.

It also includes content that is advancing or updating at a rate beyond the user's ability to read and/or understand it. In other words, animated, moving or scrolling content introduces a time limit on a users ability to read content.

In some cases, however, it is not possible to change the time limit (for example, for an auction or other real-time event) and exceptions are therefore provided for those cases.

Notes regarding server time limits

In cases where timing is not an intrinsic requirement but giving users control over timed events would invalidate the outcome, a third party can control the time limits for the user (for example, granting double time on a test).

See also 2.2.1: No Timing.

Benefits of Timing Adjustable

Examples of Timing Adjustable

Resources for Timing Adjustable

Techniques for Timing Adjustable

Sufficient Techniques for Timing Adjustable

Situation A: If there are session time limits:

  1. Providing a checkbox on the first page of a multipart form that allows users to ask for longer session time limit or no session time limit
  2. Providing a way for the user to turn the time limit off

Situation B: If a time limit is controlled by a script on the page:

  1. Providing a way for the user to turn the time limit off
  2. Providing the user with a means to set the time limit to 10 times the default time limit
  3. Providing a script that warns the user a time limit is about to expire AND Allowing the user to extend the default time limit
  4. Providing a script that warns the user a time limit is about to expire and provides a way to extend it
  5. Allowing the user to extend the default time limit

Situation C: If there are time limits on reading:

  1. G4: Allowing the content to be paused and restarted from where it was paused
  2. Providing a way for the user to turn the time limit off
  3. Using script to scroll content, and providing a mechanism to pause it
  4. Providing a mechanism to allow user to display moving, scrolling, or repeating text in a static window

Additional Techniques (Advisory) for Timing Adjustable

Failures for Timing Adjustable