SC 3.3.4 Error Prevention (Legal, Financial, Data)
Protect users from serious consequences by providing safeguards for high-stakes actions.
- Scope: Applies to actions that cause legal commitments, financial transactions, modifications/deletions of user-controllable data, or submission of test responses.
- Required Safeguards (at least one):
- Reversible: The submission can be undone or reversed after the fact.
- Checked: Data is validated for errors, and the user is given an opportunity to correct them before final submission.
- Confirmed: A mechanism is provided to review, verify, and correct information on a summary page before finalizing the submission.
- Goal: Minimize data loss and prevent costly errors by ensuring critical actions are intentional and accurate.
3.3.4 Error Prevention (Legal, Financial, Data): For applications that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true:
- Reversible: Submissions are reversible.
- Checked: Data entered by the user is checked for input errors, and the user is provided an opportunity to correct them.
- Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.
SC 3.3.4 Error Prevention (Legal, Financial, Data) supports the Understandable principle and requires that websites provide a method that prevents users from making mistakes that could have serious consequences as a result of submitting, changing or deleting legal, financial, or test data. Error prevention safeguards can help users with disabilities avoid serious and/or costly consequences (e.g., enormous loss of data, deletion of files, unintended purchases, etc.). This is really just good user experience but can be essential for users with disabilities in some situations. SC 3.3.4 Error Prevention (Legal, Financial, Data) provides for such safeguards by requiring that user-controllable data (i.e., data that users can view, modify, and/or delete) can either be reversed, verified, or confirmed. By allowing users to reverse an action (i.e., reversing a data submission by cancelling it), verify entered data (i.e., checking for input errors and allowing an opportunity to correct the errors), or confirm data submissions (i.e., allowing for the review, verification, and correcting of data prior to final submission), the loss of data can be significantly minimized and serious consequences can be avoided.
SC 3.3.4 Error Prevention (Legal, Financial, Data) is only concerned with user-controllable data that users can view and alter. Data that users do not have access to or interact with (e.g., internet logs or search engine monitoring information) is outside the scope of SC 3.3.4 Error Prevention (Legal, Financial, Data).
Note: submission of test responses is important during online training, so special attention for online training products is warranted.
Impact of Nonconformance with SC 3.3.4 Error Prevention (Legal, Financial, Data)
| Type of Disability | Description of Impact |
|---|---|
| 302.1 Without Vision | Users who are blind cannot use a mouse to interact with electronic content and typically use an assistive technology, such as a screen reader, to get audible or other alternative output for the information represented visually. To be able to navigate the content, understand its structure and relationships, and understand the meaning of content represented in graphics and images, the content must provide textual and programmatic cues in addition to the content presented purely visually. |
| 302.2 With Limited Vision | Users with limited vision may have widely different visual perception. Individuals with limited vision may or may not use assistive technologies. Therefore, in addition to textual and programmatic cues necessary for assistive technologies, ICT must also present content consistently and predictably. Users who view content with magnifiers may not pick up alerts, warnings, or other content if such content is presented outside of a consistent and predictable navigation pattern or if the content is not itself viewable at large magnification. Content that becomes distorted when magnified can also prevent some users with limited vision from being able to understand or interact with the content. |
| 302.7 With Limited Manipulation | Some users may not be able to perform actions that require fine motor control (clicking and dragging), path dependent gestures (pattern-based passcodes), or simultaneous actions (Ctrl + Alt + Del). Providing alternative means to perform the same actions, such as entering the size specifications in an input field to resize an object or allowing sequential key entries, can enable users with limited manipulation to interact with the same content. |
| 302.8 With Limited Reach and Strength | Some users may lack sufficient strength to perform actions such as squeezing, grasping, or depressing a hardware control. Some users, including those in wheelchairs or of shorter stature, may not be able to reach controls that are placed too high or too far away from where a user would access the device controls or interface. ICT designers and developers must consider a broad range of statures, strength and dexterity limitations, and the needs of wheelchair users in order to provide interfaces that are operable with limited reach and/or strength. |
| 302.9 With Limited Language, Cognitive, and Learning Abilities | Some users require more time than average to process information while others may find complicated instructions difficult to follow. Furthermore, some ICT content can distract or overwhelm users, preventing them from being able to interact with or understand other ICT content. Designers and developers of ICT must consider a broad range of cognitive abilities in order to provide ICT that is simple and easy to use. |
Applicability of Success Criteria 3.3.4 Error Prevention (Legal, Financial, Data)
| Technology | Applicability of SC 3.3.4 Error Prevention (Legal, Financial, Data) |
|---|---|
| All (Web, Software, Office documents, PDFs, Mobile Native) | Multiple methods exist for allowing users to reverse, confirm, or check and correct form submissions. Regardless of the technology used to present the form, content authors and developers must ensure that they provide at least one option to prevent errors. |