The intent of this Success Criterion is to reduce accidental activation of keyboard shortcuts. Character key shortcuts work well for many keyboard users. However, they can be inappropriate and frustrating for speech input users, whose dictation is interpreted as 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.
Even though this Success Criterion refers to character keys
, note that it's not relevant whether a shortcut can be activated using a single physical key on a keyboard, or if it requires a combination of keys to be pressed. For instance, on most full-size US and UK keyboard, the ? (question mark) symbol is accessed using Shift+/ (forward slash key next to the right-hand Shift key). On a UK keyboard, in Windows, the é (lowercase "e" with an acute accent) requires the use of AltGr+e. The specific key combination required for certain characters will also vary depending on the user's keyboard layout. However, shortcuts that use these characters still fall under the requirements of this Success Criterion. What matters is that a shortcut relies on a printable character (letters, punctuation, numbers, symbol characters), and not the number of physical keyboard keys that users need to press to trigger it.
The Success Criterion also applies to situations where a shortcut is based on a sequence of character keys – for example, pressing G and then A in quick succession to trigger an action. While the individual character key presses don't immediately trigger the action, overall these types of shortcuts still rely on a series of character keys.
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 are generally (depending on the user agent) activated using 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.
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.
Keyboard-only users are in a long issues thread. While reading the thread they accidentally hit the S key, which moves focus to the search bar at the top of the document. This causes them to lose their place and train of thought. However, a mechanism is provided to allow users to change character-key shortcuts. They change the shortcut to include another key so they can avoid future interruptions.
Web apps that use character-key shortcuts and allow users to disable and/or change these shortcuts:
Videos of speech user trouble with single character key shortcuts: