Undo: Users are provided with the ability to undo an action and to correct mistakes such that:
AA
None
Principle 3, Guideline 3.3.3
The intent of this Success Criterion is to allow users to easily undo steps in a process at any point in the process, and not just at the confirmation prior to submission.
This is especially important for people with learning and cognitive disabilities, who make many more mistakes than most people. They may realize their mistake at any point and need to correct it. For example, a work group member was booking a trip online. Due to their dyslexia, they selected a destination with a similar spelling to their intended destination. They noticed this at a later step when trying to book a hotel. The user needs to correct the mistake then, and not wait for the confirmation just prior to submission. If the user is not able to check for and correct a mistake immediately, they run the risk of forgetting their mistake later on or abandoning the whole process.
It is vital for people who are prone to making mistakes, that data they have entered correctly is not deleted when undoing a mistake. Each time the user has to reenter data, there is a new chance for new mistakes to occur. Therefore, if the user has to redo a form each time they correct one section, it can become impossible to submit all the data correctly.
For example, when booking a trip a user can make a mistake at many points, such as incorrect dates, location, hotel, flight, etc. If the user typically makes one or two mistakes in the process, they need to take breaks and double check their work a few times. If a detail is incorrect, such as booking a hotel that is too far away from an event, they must be able to fix that detail. However, if they need to redo the whole process, then when they reenter the other data they are likely to make another mistake. For example, they might invert the dates. If they need to redo the process again from the beginning a third time, they will be tired and probably make more mistakes. Hence the task becomes impossible.
Those who have difficulties accurately entering information correctly or perceiving errors will need to undo incorrect actions. It allows all users, but especially those with learning and cognitive disabilities, to re-check data entered and make necessary changes if errors have occurred.
Undo can simplify actions, reduce fear of failure, and make it possible for users to complete their task.
The benefits of having data remaining intact, even if submitted in error, allows for correction for users with poor short term memory and for those with learning disabilities.
It is part of the COGA theme to prevent the user from making mistakes and make it easy to correct mistakes when they do occur.
Issue Paper: Online Payments
See also
In a process which requires a user to enter data, confirm that at every step all of the following are true for the user: