As an IT Accessibility Analyst, one of the facets of my job is to check to see if interfaces on Web pages and software applications can be reached by pressing the Tab key, otherwise known as tabbing. While receiving keyboard focus through tabbing (along with pressing the arrow keys) is a best practice based on several guidelines and standards (i.e. Section 508 1194.21(a), Web Content Accessibility Guidelines (2.0) 2.1.1), it is not the only means of keyboard accessibility. Links, buttons, form fields and other user interfaces can also be reached with MouseKeys.
What are MouseKeys?
MouseKeys is part of Microsoft Windows accessibility features. On Windows 7, MouseKeys is part of the Ease of Access. Apple’s MAC OS also has MouseKeys, which is part of the Universal Access preferences. Users with motor control impairments (such as yours truly) can manipulate the mouse cursor by pressing keys of the numeric pad located on the right side of the keyboard. Below is a list of numeric pad keys and the mouse moves they mimic.
- “/” – Mimics pressing the right mouse button
- “*” – Mimics pressing both buttons
- “-“ – Mimics pressing the left mouse button
- “7” – Moves the mouse cursor diagonally upward to the left
- “8” – Moves the mouse cursor straight up
- “9” – Moves the mouse cursor diagonally upward to the right
- *+” – Mimics a double click
- “4” – Moves the mouse cursor to the left
- “5” – Mimics a click
- “6” – Moves the mouse cursor to the right
- “1” – Moves the mouse cursor diagonally downward to the left
- “2” – Moves the mouse cursor straight down
- “3” – Moves the mouse cursor diagonally downward to the right
- “0” – Mimics holding down the mouse button
- “.” – Mimics releasing the mouse button
Both Windows and Apple OS provide settings to adjust the pointer speed and acceleration when a numeric pad key is pressed. These settings can make all the difference to a user. For example, I have these settings set to high so I can move the mouse cursor easily without applying too much pressure while holding down the numeric pad keys with my head pointer. Otherwise, using the MouseKeys would be slow and tedious. Conversely, slower pointer speed and lower acceleration can benefit users who inadvertently apply too much pressure on the keys.
What makes MouseKeys so cool?
The major advantage of using MouseKeys is that it allows keyboard users to reach and activate interfaces that otherwise are not keyboard accessible with the Tab, arrow and Enter keys. An ideal circumstance for MouseKeys is when a Flash object does not gain keyboard focus. Through MouseKeys, keyboard users can move the mouse cursor to a Flash object control and then activate it. The pseudo mouse application also enables keyboard users to draw, paint and do other tasks where standard keyboard strokes cannot be applied.
Unlike tabbing, using the MouseKeys can allow users to reach interfaces more quickly. For instance, suppose a user wants to activate a link that is towards the bottom of a page which has three hundred other links. Even if the page has a skip-over link to bypass repetitive navigation links, tabbing to that bottom link can take a few minutes and some effort. On the other hand, holding down the numeric pad keys to move the mouse cursor to it can take five seconds.
Another benefit of MouseKeys is that keyboard users do not have to remember keyboard shortcuts to access controls such as toolbar buttons. Instead of frantically searching the Help file for a list of shortcuts, users can press the numeric pad keys to direct the mouse cursor towards interactive elements quickly.
Is MouseKeys for All Keyboard Users?
The biggest drawback of MouseKeys is that individuals with vision impairments cannot use it with screen readers since the assistive technology does not have the capability yet to track the mouse cursor. As mentioned earlier, holding down a numeric pad key can also require some pressure and motor control (regardless of whether the person uses a finger or a head pointer) to move the mouse cursor on the screen.
For these two reasons, tabbing, using the arrow keys and pressing Enter are the core keyboard accessible methods. Accordingly, these access modes are used to test websites and software applications for compliance. However, if a computer application is deemed keyboard inaccessible, it does not mean that no users with dexterity and mobility impairments can use it thanks to MouseKeys.