Functional Performance Criteria?
The Functional Performance Criteria are located in Chapter 3 of the Revised Section 508 Standards and outline overarching requirements for providing access to information and communication technology (ICT) for people with broadly defined types of disabilities. In most situations, ICT purchasers, authors, developers, and accessibility testers must rely on the technical standards to ensure that ICT is accessible to people with disabilities.
The Functional Performance Criteria come into play only in rare instances:
- Where the technical standards do not address the ICT’s features, and/or
- When the Functional Performance Criteria may be necessary to evaluate whether a design or technology conforms with the applicable Revised Section 508 Standards via equivalent facilitation. Chapter 3 of the Revised Section 508 Standards defines equivalent facilitation as a method that “results in substantially equivalent or greater accessibility and usability…than would be provided by conformance” to the technical requirements. The Functional Performance Criteria can be viewed as a catch-all or fail-safe to address technology change and allow authors and developers creativity in ensuring equal access to information and data.
Nevertheless, the technical standards support the Functional Performance Criteria, and each technical standard can generally trace its purpose and intent to one or more of the Functional Performance Criteria. Likewise, failure to meet technical standards specifically affects people with disabilities, which is addressed in the Functional Performance Criteria.
The intent of the Functional Performance Criteria is to: Define outcome-based provisions or requirements for providing ICT access to users with broadly defined types of disabilities.
Key Term: “Mode of operation” is the manner in which a user experiences, interacts with, and operates ICT. The most common modes of operation for electronic content involve a combination of vision, hearing, and touch to view and/or listen to content and interact with it by physical manipulation of controls or via a graphical user interface.
Standard: 302.1 Without Vision
302.1 Without Vision. Where a visual mode of operation is provided, ICT shall provide at least one mode of operation that does not require user vision.
Standard: 302.2 With Limited Vision
302.2 With Limited Vision. Where a visual mode of operation is provided, ICT shall provide at least one mode of operation that enables users to make use of limited vision.
Explanation
ICT must present content consistently and predictably. Users who view content with magnifiers may not pick up alerts, warnings, or other content if it is presented outside of a consistent and predictable navigation pattern or if it is not itself viewable at large magnification.
Additionally, content that becomes distorted when magnified can prevent some people with limited vision from being able to understand or interact with it. While people with limited vision can and sometimes do use screen readers (essentially using ICT without the use of any visual access), the solutions that work for people without vision are often not the optimal solution for those with limited vision.
Standard: 302.3 Without Perception of Color
302.3 Without Perception of Color. Where a visual mode of operation is provided, ICT shall provide at least one visual mode of operation that does not require user perception of color.
Standard: 302.4 Without Hearing
302.4 Without Hearing. Where an audible mode of operation is provided, ICT shall provide at least one mode of operation that does not require user hearing.
Standard: 302.5 With Limited Hearing
302.5 With Limited Hearing. Where an audible mode of operation is provided, ICT shall provide at least one mode of operation that enables users to make use of limited hearing
Explanation
Some people cannot hear sounds below certain volumes or at certain frequencies and may not be able to hear certain audio outputs from ICT. Background noise can also be problematic for people with limited hearing. Providing modes of operation that enhance audio clarity (e.g., filtering out hisses and pops, blocking sounds at specific frequencies, normalizing voice volumes, removing constant tone patterns), increase the range of volume, increase volume at higher frequencies, and/or give users control over such settings can help people with limited hearing understand, navigate, and operate ICT. People with limited hearing may also benefit from some of the same methods used to provide information to people without hearing.
Standard: 302.6 Without Speech
302.6 Without Speech. Where speech is used for input, control, or operation, ICT shall provide at least one mode of operation that does not require user speech.
Standard: 302.7 With Limited Manipulation
302.7 With Limited Manipulation. Where a manual mode of operation is provided, ICT shall provide at least one mode of operation that does not require fine motor control or simultaneous manual operations.
Explanation
Although there is no WCAG technical standard that specifically addresses alternatives for inputs requiring manual operation, an alternative method must be provided to input information or perform the operation when ICT requires fine motor control or manual dexterity for input, control, or operation.
Standard: 302.8 With Limited Reach and Strength
302.8 With Limited Reach and Strength. Where a manual mode of operation is provided, ICT shall provide at least one mode of operation that is operable with limited reach and limited strength.
Standards: 302.9 With Limited Language, Cognitive, and Learning Abilities
302.9 With Limited Language, Cognitive, and Learning Abilities. ICT shall provide features making its use by individuals with limited cognitive, language, and learning abilities simpler and easier.
Explanation
This Functional Performance Criterion covers a very broad range of language, cognitive, and learning abilities. Some of the technical requirements included in the WCAG 2.0 Success Criteria are related to this Functional Performance Criterion, including:
- 3.3.3 Error Suggestion
- 3.3.6 Error Prevention
- 2.2.1 Timing Adjustable
- 2.2.2 Pause, Stop, Hide (distracting 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.