Intent
The intent of this Success Criterion is to ensure that users receive appropriate suggestions for correction of an input error if it is possible. The WCAG 2.0 definition of "input error" says that it is "information provided by the user that is not accepted" by the system. Some examples of information that is not accepted include information that is required but omitted by the user and information that is provided by the user but that falls outside the required data format or allowed values.
Success Criterion 3.3.1 provides for notification of errors. However, persons with cognitive limitations may find it difficult to understand how to correct the errors. People with visual disabilities may not be able to figure out exactly how to correct the error. In the case of an unsuccessful form submission, users may abandon the form because they may be unsure of how to correct the error even though they are aware that it has occurred.
The content author may provide the description of the error, or the user agent may provide the description of the error based on technology-specific, programmatically determined information.
Benefits
- Providing information about how to correct input errors allows users who have learning disabilities to fill in a form successfully. Users who are blind or have impaired vision understand more easily the nature of the input error and how to correct it. People with motion impairment can reduce the number of times they need to change an input value.
Examples
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Additional Help for Correcting An Input Error
The result of a form that was not successfully submitted describes an input error in place in the page along with the correct input and offers additional help for the form field that caused the input error.
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Suggestions from a Limited Set of Values
An input field requires that a month name be entered. If the user enters "12," suggestions for correction may include
- A list of the acceptable values, e.g., "Choose one of: January, February, March, April, May, June, July, August, September, October, November, December."
- A description of the set of values, e.g., "Please provide the name of the month."
- The conversion of the input data interpreted as a different month format, e.g., "Do you mean 'December'?"
Related Resources
Resources are for information purposes only, no endorsement implied.
Techniques
Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. However, it is not necessary to use these particular techniques. For information on using other techniques, see Understanding Techniques for WCAG Success Criteria, particularly the "Other Techniques" section.
In some cases, more than one of these situations may apply. For example, when a mandatory field also requires the data to be in a specific format.
Sufficient Techniques
Select the situation below that matches your content. Each situation includes techniques or combinations of techniques that are known and documented to be sufficient for that situation.
Situation A: If a mandatory field contains no information:
- G83: Providing text descriptions to identify required fields that were not completed
- ARIA2: Identifying a required field with the aria-required property
- PDF5: Indicating required form controls in PDF forms
- SL35: Using the Validation and ValidationSummary APIs to Implement Client Side Forms Validation in Silverlight
Situation B: If information for a field is required to be in a specific data format:
- ARIA18: Using aria-alertdialog to Identify Errors
- G85: Providing a text description when user input falls outside the required format or values
- G177: Providing suggested correction text
- SCR18: Providing client-side validation and alert
- SCR32: Providing client-side validation and adding error text via the DOM
- FLASH12: Providing client-side validation and adding error text via the accessible description
- PDF22: Indicating when user input falls outside the required format or values in PDF forms
Situation C: Information provided by the user is required to be one of a limited set of values:
- ARIA18: Using aria-alertdialog to Identify Errors
- G84: Providing a text description when the user provides information that is not in the list of allowed values
- G177: Providing suggested correction text
- SCR18: Providing client-side validation and alert
- SCR32: Providing client-side validation and adding error text via the DOM
- FLASH12: Providing client-side validation and adding error text via the accessible description
- PDF22: Indicating when user input falls outside the required format or values in PDF forms
Advisory Techniques
Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.
- G139: Creating a mechanism that allows users to jump to errors
- G199: Providing success feedback when data is submitted successfully
Client-Side Scripting Techniques (Advisory)
Failures
The following are common mistakes that are considered failures of this Success Criterion by the WCAG Working Group.
Key Terms
information provided by the user that is not accepted
This includes:
- Information that is required by the Web page but omitted by the user
- Information that is provided by the user but that falls outside the required data format or values