Guideline 2.2: Don’t hurry up anyone

Provide users enough time to read and use content.

Imagine you are reading a webpage and, in the middle of that proccess, the page reloads and changes, so you can not finish the reading of the formerly page. Everybody needs different time to complete tasks, and this time is usually higher on the elderly and users with disabilities.

So this guideline is about eliminating time constraints or providing users enough additional time to allow them to complete their tasks.

2.2.1 Timing Adjustable Level A

For each time limit that is set by the content, at least one of the following is true:

  • Turn off: The user is allowed to turn off the time limit before encountering it;
  • Adjust: The user is allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting;
  • Extend: The user is warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, “press the space bar”), and the user is allowed to extend the time limit at least ten times;
  • Real-time Exception: The time limit is a required part of a real-time event (for example, an auction), and no alternative to the time limit is possible;
  • Essential Exception: The time limit is essential and extending it would invalidate the activity;
  • 20 Hour Exception: The time limit is longer than 20 hours.

This success criterion helps ensure that users can complete tasks without unexpected changes in content or context that are a result of a time limit. This success criterion should be considered in conjunction with Success Criterion 3.2.1, which puts limits on changes of content or context as a result of user action.

Compulsory

If there are session time limits:
  • Provide 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
  • Provide a way for the user to turn the time limit off
If a time limit is controlled by a script on the page:
  • Provide a way for the user to turn the time limit off
  • Provide a means to set the time limit to 10 times the default time limit
  • Providing a script that warns the user a time limit is about to expire AND allow the user to extend the default time limit
If there are time limits on reading:
  • Allow the content to be paused and restarted from where it was paused
  • Provide a way for the user to turn the time limit off
  • Use script to scroll content, and provide a mechanism to pause it
  • Provide a mechanism to allow users to display moving, scrolling, or auto-updating text in a static window or area

Recommended

  • Use a script to poll the server and notify a user if a time limit is present

Failures

  • Using meta redirect with a time limit
  • Using meta refresh with a time-out
  • Using server-side techniques to automatically redirect pages after a time-out
  • Including scrolling content where movement is not essential to the activity without also including a mechanism to pause and restart the content

2.2.2 Pause, Stop, Hide Level A

For moving, blinking, scrolling, or auto-updating information, all of the following are true:

  • Moving, blinking, scrolling: For any moving, blinking or scrolling information that (1) starts automatically, (2) lasts more than five seconds, and (3) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it unless the movement, blinking, or scrolling is part of an activity where it is essential; and
  • Auto-updating: For any auto-updating information that (1) starts automatically and (2) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it or to control the frequency of the update unless the auto-updating is part of an activity where it is essential.

Notes:

  1. For requirements related to flickering or flashing content, refer to Guideline 2.3.
  2. Since any content that does not meet this success criterion can interfere with a user’s ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion.
  3. Content that is updated periodically by software or that is streamed to the user agent is not required to preserve or present information that is generated or received between the initiation of the pause and resuming presentation, as this may not be technically possible, and in many situations could be misleading to do so.
  4. An animation that occurs as part of a preload phase or similar situation can be considered essential if interaction cannot occur during that phase for all users and if not indicating progress could confuse users or cause them to think that content was frozen or broken.

Compulsory

  • Allowing the content to be paused and restarted from where it was paused
  • Use script to scroll content, and providing a mechanism to pause it
  • Creatie content that blinks for less than 5 seconds
  • Use a technology to include blinking content that can be turned off via the user agent
  • Set animated gif images to stop blinking after n cycles (within 5 seconds)
  • Use scripts to control blinking and stop it in five seconds or less (Scripting)
  • Use a control in the Web page that stops moving, blinking, or auto-updating content
  • Provide a link, button, or other mechanism that reloads the page without any blinking content

Recommended

  • Provide a mechanism to stop all content that blinks within a Web page
  • Provide the user with a means to stop moving content even if it stops automatically within 5 seconds

Failures

  • including scrolling content where movement is not essential to the activity without also including a mechanism to pause and restart the content
  • using the blink element
  • using text-decoration:blink without a mechanism to stop it in less than five seconds
  • a script that causes a blink effect without a mechanism to stop the blinking at 5 seconds or les
  • an object or applet, such as Java or Flash, that has blinking content without a mechanism to pause the content that blinks for more than five seconds

2.2.3 No Timing Level AAA

Timing is not an essential part of the event or activity presented by the content, except for non-interactive synchronized media and real-time events.

Compulsory

  • Allow users to complete an activity without any time limit

2.2.4 Interruptions Level AAA

Interruptions can be postponed or suppressed by the user, except interruptions involving an emergency.

Compulsory

  • Provide a mechanism to postpone any updating of content
  • Provide a mechanism to request an update of the content instead of updating automatically
  • Use scripts to make nonessential alerts optional (Scripting)

Failures

  • Using meta redirect with a time limit
  • Using meta refresh with a time-out

2.2.5 Re-authenticating Level AAA

When an authenticated session expires, the user can continue the activity without loss of data after re-authenticating.

Compulsory

Provide options to continue without loss of data:

  • Saving data so that it can be used after a user re-authenticates; or
  • Encoding user data as hidden or encrypted data in a re-authorization page

Failures

  • Having a session time limit without a mechanism for saving user’s input and re-establishing that information upon re-authentication

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