Understanding SC 2.1.4:Character Key Shortcuts (Level A)
Intent
The intent of this Success Crition is to reduce accidental activation of keyboard shortcuts. Character key shortcuts work well for many keyboard users, but are inappropriate and frustrating for speech input users — whose means of input is strings of letters — and for keyboard users who are prone to accidentally hit keys. To rectify this issue, authors need to allow users to turn off or reconfigure shortcuts that are made up of only character keys.
Note that this success criterion doesn't affect components such as listboxes and drop-down menus. Although these components contain values (words) that may be selected by one or more character keys, the shortcuts are only active when the components have focus. Other components such as menus may be accessed or opened with a single non-character shortcut (e.g., Alt or Alt+F) before pressing a single character key to select an item. This makes the full path to invoking a menu a two-step shortcut that includes a non-printable key. Accesskeys are also not affected because they include modifier keys.
Speech Input users generally work in a single mode where they can use a mix of dictation and speech commands. This works well because the user knows to pause before and after commands, and commands are usually at least two words long. So, for instance, a user might say a bit of dictation, such as "the small boat", then pause, and say a command to delete that dictation, such as "Delete Line". In contrast, if the user were to say the two phrases together without a pause, the whole phrase would come out as dictation (i.e., "the small boat delete line"). Although speech input programs often include modes that listen only for dictation or only for commands, most speech users use the all-encompassing mode all the time because it is a much more efficient workflow. It could decrease command efficiency significantly if users were to change to command mode and back before and after issuing each command.
Speech users can also speak most keyboard commands (e.g., "press Control Foxtrot") without any problems. If the website or app is keyboard enabled, the speech user can also write a native speech macro that calls the keyboard command, such as "This Print" to carry out Ctrl+P.
Single-key shortcuts are the exception. While using single letter keys as controls might be appropriate and efficient for many keyboard users, single-key shortcuts are disastrous for speech users. The reason for this is that when only a single key is used to trip a command, a spoken word can become a barrage of single-key commands if the cursor focus happens to be in the wrong place.
For example, a speech-input user named Kim has her cursor focus in the main window of a web mail application that uses common keyboard shortcuts to navigate ("k"), archive ("y") and mute messages ("m"). A coworker named Mike enters her office and says "Hey Kim" and her microphone picks that up. The Y of "hey" archives the current message. K in "Kim" moves down one conversation and M mutes a message or thread. And, if Kim looks up and says "Hey Mike" without remembering to turn off the microphone, the same three things happen in a different sequence.
A user interacting with a webpage or web app that doesn't use single-character shortcuts doesn't have this problem. Inadvertent strings of characters from the speech application are not interpreted as shortcuts if a modifier key is required. A speech user filling in a text input form may find that a phrase that is accidentally picked up by the speech microphone results in stray text being entered into the field, but that is easily seen and undone. The Resources section of this page contains links to videos demonstrating these types of issues.
Benefits
- Speech users will be able to turn off single-key shortcuts so they can avoid accidentally firing batches of them at once. This will allow speech users to make full use of programs that offer single-key shortcuts to keyboard users.
- Keyboard-only users who have dexterity challenges can also be prone to accidentally hitting keys. Those users would be able to avoid problematic single character shortcuts by turning them off or modifying them to include at least one non-character key.
- Allowing all shortcut keys to be remapped can help users with some cognitive disabilities, since the same shortcuts can be assigned to perform the same actions across different applications.
Examples
Disable Shortcuts
A mechanism is provided to allow users to disable character-key shortcuts. The character key shortcuts are not the only way to carry out these commands. A speech user disables the shortcuts and can prevent words that are picked up by the microphone from triggering single-key shortcuts.
Alternate Control
A keyboard-only user is in a long issues thread. While reading the thread she accidentally hits the S key, which moves focus to the search bar at the top of the document. This causes her to lose her place and her train of thought. However, a mechanism is provided to allow users to change character-key shortcuts. She changes the shortcut to include another key so she can avoid future interruptions.
Related Resources
Resources are for information purposes only, no endorsement implied.
Web apps that use character-key shortcuts and allow users to disable and/or change these shortcuts:
- Gmail
- WordPress
Videos of speech user trouble with single character key shortcuts:
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.
Sufficient Techniques
Failures
The following are common mistakes that are considered failures of this Success Criterion by the WCAG Working Group.
Key Terms
hardware and/or software that acts as a user agent, or along with a mainstream user agent, to provide functionality to meet the requirements of users with disabilities that go beyond those offered by mainstream user agents
functionality provided by assistive technology includes alternative presentations (e.g., as synthesized speech or magnified content), alternative input methods (e.g., voice), additional navigation or orientation mechanisms, and content transformations (e.g., to make tables more accessible).
Assistive technologies often communicate data and messages with mainstream user agents by using and monitoring APIs.
The distinction between mainstream user agents and assistive technologies is not absolute. Many mainstream user agents provide some features to assist individuals with disabilities. The basic difference is that mainstream user agents target broad and diverse audiences that usually include people with and without disabilities. Assistive technologies target narrowly defined populations of users with specific disabilities. The assistance provided by an assistive technology is more specific and appropriate to the needs of its target users. The mainstream user agent may provide important functionality to assistive technologies like retrieving Web content from program objects or parsing markup into identifiable bundles.
Assistive technologies that are important in the context of this document include the following:
- screen magnifiers, and other visual reading assistants, which are used by people with visual, perceptual and physical print disabilities to change text font, size, spacing, color, synchronization with speech, etc. in order to improve the visual readability of rendered text and images;
- screen readers, which are used by people who are blind to read textual information through synthesized speech or braille;
- text-to-speech software, which is used by some people with cognitive, language, and learning disabilities to convert text into synthetic speech;
- speech recognition software, which may be used by people who have some physical disabilities;
- alternative keyboards, which are used by people with certain physical disabilities to simulate the keyboard (including alternate keyboards that use head pointers, single switches, sip/puff and other special input devices.);
- alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations.
satisfying all the requirements of a given standard, guideline or specification
alternative means of triggering an action by the pressing of one or more keys
process or technique for achieving a result
The mechanism may be explicitly provided in the content, or may be relied upon to be provided by either the platform or by user agents, including assistive technologies.
The mechanism needs to meet all success criteria for the conformance level claimed.
series of user actions where each action is required in order to complete an activity
Successful use of a series of Web pages on a shopping site requires users to view alternative products, prices and offers, select products, submit an order, provide shipping information and provide payment information.
An account registration page requires successful completion of a Turing test before the registration form can be accessed.
the content would not conform if that technology is turned off or is not supported
mechanism for encoding instructions to be rendered, played or executed by user agents
As used in these guidelines "Web Technology" and the word "technology" (when used alone) both refer to Web Content Technologies.
Web content technologies may include markup languages, data formats, or programming languages that authors may use alone or in combination to create end-user experiences that range from static Web pages to synchronized media presentations to dynamic Web applications.
Some common examples of Web content technologies include HTML, CSS, SVG, PNG, PDF, Flash, and JavaScript.
any software that retrieves and presents Web content for users
Web browsers, media players, plug-ins, and other programs — including assistive technologies — that help in retrieving, rendering, and interacting with Web content.
a part of the content that is perceived by users as a single control for a distinct function
Multiple user interface components may be implemented as a single programmatic element. "Components" here is not tied to programming techniques, but rather to what the user perceives as separate controls.
User interface components include form elements and links as well as components generated by scripts.
What is meant by "component" or "user interface component" here is also sometimes called "user interface element".
An applet has a "control" that can be used to move through content by line or page or random access. Since each of these would need to have a name and be settable independently, they would each be a "user interface component."