Accessibility of Apple’s Magic Trackpad

Written By: Peter Abrahams
Content Copyright © 2010 Bloor. All Rights Reserved.

Apple’s recent announcement of new models of the iMac include faster processing and graphics as we would expect; but the really interesting announcement for the accessibility community is the Magic Trackpad.

The previous iMac announcement introduced the Magic Mouse which was a very elegant looking device with some limited gesture recognition. The problem with the Magic Mouse was that it was still just a mouse and therefore no use to people with limited or no vision, nor to people suffering from RSI (I have limited RSI and I could not use the Magic Mouse).

The Magic Trackpad is another elegant device, it is a plain glass square (about 13cm square) which has the same depth and rake as the standard keyboard so can be placed as a seamless extension to the right or the left of the keyboard. It is operated by touches and gestures using one, two, three and four fingers. It can also be used in conjunction with VoiceOver (the text to speech technology on the iMac).

Apple bought a company a few years ago that developed the technology behind the Trackpad; interestingly this company developed the technology specifically to help users with Repetitive Strain Injury (RSI). The technology helps because it removes two of the major contributors to RSI, having to grip a mouse for long period and small movements, like mouse clicks, that require pressure. The gestures used on the Trackpad do not require any grip or pressure. Further, the Trackpad is very close to the keyboard—this reduces movements of the arm some distance to the right which is another potential cause of RSI.

The Trackpad has a variety of gestures that can reduce the effort required to initiate some repetitive tasks, for example 3-finger-swipe for page forward or backward, this gestures works in many applications, possibly the most important of which is web browsing. Other useful gestures are scrolling (including left-right and up-down and both together), rotate, application zoom in and out, screen zoom in and out. All of the gestures are easy to use and become second nature very quickly. There is one which I believe should be improved, the 4-finger-swipe left/right is intended to switch applications, it works well to start with, the swipe brings up the list of active applications, a 2-finger-swipe will then move the focus to the application of interest but you then have to move to the keyboard return key to switch. What I would like, and have recommended to Apple, is that the switch can be made by a finger-tap. Interestingly the 4-finger-swipe-down opens Exposé and that works as I would expect.

If you want to know how to use the gestures and what options there are then the system preference panel has all the information with little video clips of each gesture.

So these standard gestures provide great support for anyone with RSI and I think are a great usability aid for anyone who normally uses a mouse.

The Trackpad has also been designed to enhance the experience for VoiceOver users. There are a much wider range of gestures and gestures combined with keyboard depressions. It is a complex system and I have only got a general feeling as to how it would be used. There are three main characteristics:

  • Some gestures are defined by where on the Trackpad they are performed for example 2-finger-double-tap near the top of the Trackpad, is different to 2-finger-double-tap on the right.
  • If there is a list of items you can go directly to the required one by touching the relevant part of the Trackpad, for example if there are 9 active applications and you want to go to the seventh you would touch the Trackpad near the bottom and VoiceOver will read out the application name, an experienced user will hit it spot on, a newer user might be one application out but can quickly get to the right one by moving up or down a bit.
  • To make it easier for a VoiceOver user to work with a sighted person the area of the screen in VoiceOver focus is highlighted and the rest of the screen is greyed out.

All gestures have an equivalent keyboard implementation which may require the use of several keystrokes. The gestures provide a more intuitive and faster implementation. The Trackpad is therefore a welcome new input device for people who are blind or have limited vision.

The new iMac comes with the Magic Mouse in the box and the Magic Trackpad is only available as an extra. The Trackpad is undoubtedly the preferred option for people with RSI or vision impairments, I believe that many able bodied users will find the Trackpad superior to the Mouse. It will be interesting to see which one comes in the box with the next generation of iMac, my money is on the Trackpad.