Accessibility Features in OS X

For this class, I've been using a Macbook Air running OS X version 10.9, also known as Mavericks.  To gain a better understanding of how to make technology more accessible to a wide range of students, I took a look at the accessibility features Apple has built in to OS X.  In the system menu, Apple divides their features into three categories: seeing, hearing, and interacting.

Seeing

The graphical user interface has become standard in modern operating systems, but these interfaces rely on the user being able to see the screen.  Apple has built several tools into OS X to assist users with limited vision.  First, all Macs contain VoiceOver, a screen reader which also describes what is happening on the screen and responds to commands from keyboards, gestures on the touchpad, and other input devices (OSX Accessibility, 2014).  For users with limited color vision, OS X has options to invert colors (so that items which normally appear black instead appear white and vice versa), switch the display to greyscale, or enhance the display contrast (Merrick, 2013).  The fine control these tools offer over the appearance of the screen can significantly increase the visibility for certain users.  Finally, some people just need things to appear bigger in order to see clearly.  For these users, OS X includes tools to magnify the screen which can be controlled using keyboard shortcuts, a mouse scroll wheel, or gestures on a trackpad (OS X Accessibility, 2014).  Users also have a choice of whether to magnify the entire screen or to use the cursor as a magnifying glass to zoom in on only a portion of the screen (Merrick, 2013).

Hearing

Most people receive countless notifications on their computer, such as alerts for new emails, a message in a chat client, or notifications for various apps and a person who is heard of hearing is likely to miss most of these alerts.  To get around this, OS X has an option to produce a screen flash where the computer screen briefly lightens to provide notifications (Merrick, 2013).  Users with hearing loss in one ear will sometimes miss audio in recordings with distinct tracks intended for each ear.  For these users, Apple offers an option to enable mono audio, forcing both tracks to play through both speakers (OS X Accessibility, 2014).

Interacting

There are a variety of physical disabilities  which can make traditional input devices extremely challenging to use.  Using a mouse and keyboard requires a fair amount of fine motor control, which can be severely limited by many neurological disorders including dystonia, Parkinson's, and traumatic brain injury.  A wide range of disorders, diseases, and injuries can even remove the use of a limb entirely.  Even milder disorders such as arthritis, tendonitis, or carpal tunnel syndrome can limit the range of motion in a person's hand or wrist enough to make input devices challenging to use.  For these users, Apple has several accessibility options which change how these input devices work.

While every user occasionally hits the wrong key on the keyboard, certain disabilities can make those errors much more common.  The Slow Keys option can provide a useful workaround by requiring a key to be held down, not just tapped, in order to register as a key press and the length of time can be set by the user (Merrick, 2013).  A related option, Sticky Keys, makes it easier to enter keyboard combinations (such as Command+c to copy) by "remember" when the Command key has been pressed until the next key is entered, removing the need for a user to hold down Command and reducing the range of motion needed for these combinations (Merrick, 2013).  If these options are not enough to make a standard keyboard accessible, Apple offers an on-screen keyboard which can be used with a mouse, trackpad, or other input devices (OS X Accessibility, 2014).  

To make the mouse and trackpad easier to use, Apple offers an option to use keys from the number pad to move the cursor, rather than dragging a mouse (OS X Accessibility, 2014).  Pressing buttons requires a much smaller range of motion than moving a mouse, as well as a slightly different grip, and may therefore be more manageable for some.

In spite of these features, some people are still unable to use the keyboard, mouse, and trackpad either due to severely limited movement (such as paralysis) or a significant lack of fine motor control (such as in many movement disorders).  For these users, as well as those who just want to feel like they live in the future, Apple includes voice commands (Merrick, 2013).  Voice commands can be used to perform quite a few functions, such as opening and closing applications, that would normally be done using a mouse or keyboard.  OS X also includes a dictation tool, allowing users to speak rather than type text.

Beyond System Settings

It is not only the built-in options that make OS X accessible to a variety of users, but its support for peripherals that can greatly enhance the experience for certain users.  For example, blind users may benefit from a braille display which can connect to OS X via Bluetooth or USB (Braille displays for OS X, 2014).  Many of these displays are compatible with Voice Over, allowing information from the screen to be presented via audio, the braille display, or both.

With the release of Mavericks, Apple also began supporting technology known as switches (Lee, 2013).  Users with severely limited mobility, often due to paralysis or severe degenerative diseases, may be limited to extremely simple gestures.  Switches allow users to control a computer using basic movements such as pressing a large button or blowing a straw.  Stephen Hawking, who suffers from advanced ALS, currently uses a switch that detects small twitches in his cheek as his only means of controlling the computer he uses for communication and mobility (Hawking, n.d.).  OS X currently offers more options to support and customize the use of switches than most other operating systems.

While not strictly an accessibility feature, Apple offers options to customize gesture commands used with a trackpad or Magic Mouse (a mouse with a touch sensitive surface for gesture recognition), which can be further expanded and customized with the help of certain apps (Penderworth, 2013).  Many people are limited only on one side, such as in the case of hemispherical dystonia, so tools which allow a user to add more functionality to their "good" side can significantly increase the accessibility of technology.

For other examples of how technology can make education more accessible, visit my adaptive & assistive technology project.

References

Braille Displays for OSX.  (2014).  Apple, Inc.  Retrieved from http://www.apple.com/accessibility/osx/braille-display.html.

Hawking, S.  (n.d.).  The computer.  Retrieved from http://www.hawking.org.uk/the-computer.html.

Lee, S.  (2013, October 24).  Apple again raise the accessibility bar with os x switch control.  Opening Accessibility.  Retrieved from http://opendirective.net/blog/2013/10/apple-again-raise-the-accessibility-bar-with-os-x-switch-control/.

Merrick, J.  (2013, June 3).  Os x accessibility 101.  tuts+.  Retrieved from http://computers.tutsplus.com/tutorials/os-x-accessibility-101--mac-50001.

Penderworth, J.  (2013, March 12).  Setting up custom trackpad gestures on your mac.  tuts+.  Retrieved from http://computers.tutsplus.com/tutorials/setting-up-custom-trackpad-gestures-on-your-mac--mac-47668.

OS X Accessibility.  (2014).  Apple, Inc.  Retrieved from http://www.apple.com/accessibility/osx/.