Click, Tap, or Stroke?

Microsoft tailored Windows 8 for use with touch-screen input. Would you improve your productivity by switching from mouse or trackpad to touch-screen too?

Microsoft has made it clear that it sees future Windows users interacting primarily through touch-sensitive displays, or touch-screens, although you can still use Windows 8 with a regular display, keyboard, and mouse/trackpad.

In contrast it is Apple that has already sold far more touch-screen devices than currently run Windows 8, leaving Microsoft to face a very long and steep road to compete with the the success of the iPad Touch, iPhone, and iPad. Macs remain driven primarily by mouse or trackpad, and there are no signs of OS X going gooey over touch-screens.

In principle

Touch-screens are much more recent than the mouse or graphics tablet, starting to appear in the early 1980s, when they mainly used resistive technology. In these, the outer layers of the display incorporate two thin resistive sheets which, when pressed together, allow the X and Y coordinates of the pressure point to be determined.

Now most commonly used in hostile environments where the display will become wet or contaminated, you probably signed your name on one to acknowledge receipt of a parcel, for instance. As they require significant pressure, and do not need warm bare flesh to operate, they are often used with a stylus rather than finger. In their present form, such resistive displays are unsuitable for high-resolution computer touch-screens.

The great majority of modern touch-screens – including those running iOS – use capacitive rather than resistive sensing. The principle is that, when the underside of the display is coated with a transparent conductor such as indium tin oxide (ITO), touching the surface with a conductive object such as a finger changes the local electrostatic field, allowing location of the point of contact.

This works best with warm and very slightly moist skin; if your fingertip is cold and dry, or insulated within a glove, insufficient change results, and the screen does not work. You can buy special conductive gloves or styluses for use when bare fingers will not work. Variants in the way that capacitance is produced and sensed account for the different properties encountered in different touch-screens, but these devices do not require pressure, only proximity or gentle contact.

In practice

As we have learned with the mouse and other input devices, whilst basic technology is important, our user experience is largely determined by the way in which that technology is implemented, the human factor; screw the ergonomics up and it is useless. Poor implementations of touch-screens, such as vertically-mounted panels, can be very fatiguing, resulting in what has become popularly known as ‘gorilla arm’.

One of the greatest conflicts in putting touch-screens into popular use is finding the best compromise position to optimise both touch and visual access to the display.

We naturally find it easiest to use our fingers when they are positioned just in front of the body, well below shoulder height, with the forearms supported. Looking at a display mounted in that position requires the neck to be flexed, and the plane of the display angled to bring it perpendicular to your gaze. Thus working for long periods at vertically mounted touch-screens, optimised for vision, or those positioned for best finger access, is likely to lead to fatigue and discomfort in some part of the body.

Tablets and phones, being smaller, lighter, and generally used for shorter periods of less intense user interaction, do not commonly result in gorilla arm or neck strain. They are also normally used with on-screen keyboards, so you do not have to switch repeatedly between touching the screen and tapping on a separate keyboard. For heavy-duty text input, a separate conventional keyboard remains unrivalled, particularly for touch-typists.

Coupling a full-size off-screen keyboard with a touch-screen display causes even worse positional conflicts: whilst the display may be slightly better placed for vision, you then end up stretching further forward in order to touch it. You can almost hear the personal injury lawyers preparing their papers for the next big office ailment after repetitive strain injury (RSI).

My more extensive guidance on good working position and ergonomics is here.

Pros and cons

Touch-screens do have some unique advantages, particularly in enabling the direct manipulation of items being displayed, for instance moving objects on screen such as pieces of jigsaw puzzle. For naive users like children, many elements of the graphical interface are far simpler to use, easing access to dialogs, buttons, and the like. Users also find it quicker to achieve proficiency in precision drawing, as might otherwise be accomplished using a larger graphics tablet.

There is no doubt that learning to move a stylus over a detached tablet whilst watching the results on a separate display can be tough, and many artists have found an iPad far more direct and expressive. Sadly for the time being Wacom’s Cintiq touch-screens remain too costly for most users to try, and Modbook’s modified MacBook Pro has also failed to catch on.

Nowhere is the conflict between touch-screens and usability better illustrated than in Microsoft Office 2013 (for Windows). If there is any suite of apps that is keyboard-bound, it is Office, where most tasks consist of protracted text or numeric entries, punctuated by command-key shortcuts.

The changes introduced in Office 2013 to accommodate Windows 8’s predilection for touch-screens are minimal, with even enthusiastic users describing them as a reactionary stopgap. Whether a fuller Metro-flavoured Office, aimed at Microsoft Surface users, will prove any more satisfying and productive remains to be seen when the Office team have plucked up the courage to implement it.

So while some Mac users will find touch-screens such as Wacom’s new Cintiq pen displays a valuable and effective addition to their input devices, we will still need OS X to work well with a broad range, from the venerable mouse, tracker ball (an upside-down mouse in which you move the ball), graphics tablet, more novel trackpads, keyboards, and even less conventional devices such as joysticks and more exotic games controllers.

The only real caution that needs to be exercised is with drivers and other software that may be required to get the best out of an input device. Because these devices operate fairly low down in OS X, an old and creaky software driver can easily render OS X unstable.

Vendors of input devices have a worrying tendency to put more effort and care into their hardware, and their OS X software can lag releases of OS X, breeding problems. Prefer those that can still work well with Apple’s standard System Preferences panes, so that years after their manufacturer has ceased supporting any driver, you can continue to use your favourite device.

Choosing an input device is a very personal matter, also highly dependent on the tasks to be accomplished and the apps to be used. Although anathema to many organisations, it is usually best to encourage users to work with their preferred devices, and to allow them to switch between devices when that will enhance their productivity.

Dishing out a standard mouse and keyboard to everyone and limiting them to those alone is not a good way to realise the investment made in computing equipment, but is an excellent way of alienating talent and skills instead of exploiting them.


For 15 years, the Mac’s mainstream input device, apart from the keyboard, was the mouse. This blossomed from the strictures of the original single-button version to today’s wireless Magic Mouse, with multiple buttons and an upper surface that can be used for gestures such as swiping and scrolling.

The Apple Magic Trackpad and Wireless Keyboard. Courtesy of, and © Apple.
The Apple Magic Trackpad and Wireless Keyboard. Courtesy of, and © Apple.

Five years ago, Apple offered an alternative that many now prefer to any mouse: its Magic Trackpad. A standalone and slightly larger version of the multitouch trackpad incorporated in laptop models such as the MacBook Pro, it is only available in wireless form. Because of their far smaller size, trackpads only operate using relative coordinates, in contrast to the absolute coordinates offered by full-sized graphics tablets, which makes them less useful for freehand and precision drawing, for instance.

Among the trickiest gestures using a trackpad is the long distance drag and drop, most commonly when placing items in the Trash, something easily accomplished with a mouse. Regular trackpad users tend to employ workarounds, such as the Move To Trash command in the Finder’s contextual menu.

The standard Trackpad pane includes demonstration movies of gestures.
The standard Trackpad pane includes demonstration movies of gestures.

With the trackpad comes a pane for System Preferences that allows you to configure the gestures supported, and their effects. This is notable for its beautiful video clips demonstrating each gesture, which help swell the pane to almost 100 MB in size.

However, as with trackpads built into laptop models, its most significant failing is the continued omission of control over the sensitivity of the trackpad. Sometimes, perhaps following a system software update, trackpads can become so sensitive that the finger does not even have to make contact with the pad, making control highly frustrating.

MagicPrefs extends Apple's trackpad support, including control over sensitivity.
MagicPrefs extends Apple’s trackpad support, including control over sensitivity.

MagicPrefs, free from here, addresses this shortcoming with a global ‘gesture triggering’ control which alters a number of factors in the way in which taps and swipes are sensed.

Graphics Tablets

Drawing with a mouse or trackpad is neither easy nor sufficiently controllable to be precise. For many years professional artists and designers have used A4 or larger graphics tablets with a stylus, which predate even the mouse, originating in 1957. Although others can be used with Macs, Wacom’s products have dominated the market almost completely.

With their larger size, each point on the tablet can be mapped to a corresponding point on the display, providing ultimate positional precision in this ‘absolute’ mode. When you want to take the pointer to the top left of the display, you place the stylus at the top left of the tablet.

Tablets are also pressure sensitive, which can be used to control the intensity of marks drawn, thickness of line, rate of colour application, or similar – something not possible with the on/off controls of mouse or trackpad. Unfortunately such professional tablets are expensive, particularly in larger sizes to match big displays.

Wacom's inexpensive Bamboo tablets have good pen support.
Wacom’s inexpensive Bamboo tablets have good pen support.

With the sudden popularity of trackpads, Wacom is offering its Bamboo ‘Pen and Touch’ range, generally smaller in size and with support for trackpad-like gestures, including relative positioning and the use of fingers as well as a stylus. If you have become used to using a trackpad, a Bamboo tablet in ‘touch’ mode can behave quite similarly.

Bamboo tablets also support touch input if you wish.
Bamboo tablets also support touch input if you wish.

Unfortunately standard models are USB wired; Wacom’s wireless add-on kit costs around £32 (inc VAT) and irritatingly does not talk to built-in Bluetooth hardware, requiring its own USB dongle to act as receiver. Wacom also has a less-than-perfect record of delivering robust drivers for its tablets, but has addressed this for the Bamboo range, with a comprehensive pane for System Preferences, and a palette of additional tools.

One last tip: if you switch to a trackpad, tablet, or touch-screen, keep a wired USB mouse handy for emergencies.

Updated from the original, which was first published in MacUser volume 29 issue 04, 2013.