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The Past, Present, and Future of Touch

How today’s touchscreen tech put the world at our fingertips


Let your fingers do the walking: Designing software for the human hand

Enlarge / Touch software trades menus, checkboxes, and cursors for big, tappable buttons.
Andrew Cunningham

The touchscreens themselves are important, but the software that powers today's phones and tablets is even more vital. Modern phone and tablet operating systems are made for touch first, and they're designed differently from software made to be used with a keyboard, mouse, or even a stylus.

Let's step back to 2001 or so, when Microsoft first introduced its concept of the "Tablet PC." These early tablets ran a version of Windows XP Professional called the "Tablet PC Edition." It supported pen input and came with a small suite of applications for handwritten notes and other pen-centric tasks.

Despite these additions, the Tablet PC Edition of Windows XP was very much Windows XP with a few new pieces laid on top of it. The pens could be acceptable pointing devices (subject to the quality and accuracy of the touchscreen), but the vast majority of the operating system and the applications that ran on it were designed with the far-more-prevalent keyboard and mouse in mind. (Microsoft Office 2013 is a more recent example of software that was designed for a mouse and keyboard first.) This isn't necessarily a bad thing, but it does make it much more difficult to use with a touchscreen.

Modern operating systems with a touch-first approach are more finger-friendly in two important ways: responsiveness and size.

When we say "responsiveness," we're not only talking about an operating system that responds quickly and accurately to input, though that's certainly very important. When you touch something in the real world, it reacts to your touch immediately, and the operating systems that feel the best to use are the ones that act the same way. Windows Phone makes a point of running smoothly even on low-end hardware, to make sure that its phones feel satisfying whether they cost $200 or were free with a contract. But consistency is also an important element of responsiveness. Android's "Jelly Bean" update included "Project Butter," which focused on making the operating system run at 60 frames-per-second as often as possible. This was intended to improve the sometimes-inconsistent performance of older Android versions.

Enlarge / Some apps use tricks to make hard-to-tap elements a bit easier to interact with. Chrome for Android will pop up a helpful magnifying-glass style box when you attempt to tap in an area with several links grouped close together, for instance.
Andrew Cunningham

Another important element here are the little nuances that make using a touch-and-gesture-based operating system feel more natural: this means scrolling that speeds up, slows down, and gains momentum based on how you're touching the screen. When you can't scroll anymore, the OS will usually move and snap back into place to let you know that you can't scroll further (commonly called "rubber-banding"). These behaviors let the user know that their input was recognized, even if that input didn't actually do anything—if yesterday's PCs used blinking lights to demonstrate that they were working, today's touch devices use slick transitions and animations.

The size of onscreen elements is also crucial to a good touch experience—fingers aren't precise enough to easily deal with a bunch of nested menus, checkboxes, and buttons like Windows or OS X use. Instead, you often have to sacrifice information density in favor of making your UI larger. Most touch operating systems have some general guidelines to follow when developing touch applications, but Apple's are well-defined and simple to explain, so we'll use iOS as an example.

Apple's Human Interface Guidelines for iOS define "the comfortable minimum size of a tappable UI element" as being 44 by 44 "touch points" large. On non-Retina displays like the iPad mini or iPhone 3GS, a "touch point" and a pixel are the same size; on a Retina display like the iPad 4 or iPhone 5, one touch point is one 2×2 square of pixels (since a Retina display has four times as many pixels as a non-Retina display). On a phone, the physical size of one of these tappable elements is about 0.38" (or 9.7mm) large, while on an iPad it's about 0.47" (11.9mm) large. Developers are free to use larger or smaller elements, but these measurements exist to give developers a general idea of how much space you need to prevent accidental button presses, mis-registered touches, and anything else the user didn't intend to do.

Enlarge / The red squares laid over top of the iPhone's dialer app represent Apple's minimum recommended size for tappable onscreen elements.
Andrew Cunningham


As this software has matured and people have become more used to it, newer phones and tablets have become even more button-averse. Stock Android switched out its hardware buttons for onscreen software buttons (which, like software keyboards, are context-sensitive and can change based on the application you're running). Windows 8 and Windows RT tablets still retain a Windows button, but they rely on gestures and swipes from the edge of the screen. The BlackBerry Z10 does away with even a home button, relying entirely on gestures for not just OS navigation, but also for waking the phone from sleep.

Look around you—touch is everywhere

Enlarge / The best touch-enabled Ultrabooks (like the Dell XPS 12 pictured here) include touch capability without getting in the way of the standard PC functions.
Andrew Cunningham

The success of touch-driven smartphones and tablets have had two overarching effects: for one, consumers are beginning to expect touch, even in places where it hasn't always been (more than once, I've gone back to my MacBook Air after using a Windows 8 Ultrabook for a few days, only to catch myself trying to touch the screen). On the other side of that coin, hardware manufacturers seeking to capitalize on the success of other touch-driven devices have been experimenting with touchscreens in everything from PCs to watches.

For PCs, Windows 8 has given rise to a new class of convertible laptops that try to serve the needs of both touch users and Windows desktop users. These experiments haven't always worked out, but the best of them—designs like Lenovo's IdeaPad Yoga and Dell's XPS 12—add touch capabilities without diminishing the devices' utility as regular laptops. Sony's PlayStation Vita, its forthcoming PlayStation 4, and Nintendo's Wii U all also use touchscreens as a secondary means of input in addition to the respective consoles' signature controllers. All of these devices show that touch can be additive as well as disruptive—it can improve already good devices just as readily as it replaced the ungainly smartphones and tablets of the early-to-mid 2000s.

Other experiments on the PC side of the fence attempt to define completely new products. PCs like Sony's Tap 20, Lenovo's IdeaCentre Horizon 27, and Asus' Transformer AiO all combine a traditional all-in-one PC with a large touchscreen that multiple people can gather around at once. This seems especially conducive to entertainment and education—multiplayer games and collaborative exercises are commonly touted as selling points for these big new screens.

Enlarge / Big touchscreens like the one on Sony's Tap 20 open the door to multiple simultaneous users.

Touch seems equally likely to move down into smaller screens. More than one company is rumored to be working on a "smart watch" to augment (or even replace select functions of) your smartphone. It's a fair bet that if these products come to pass, more than one of them will work touchscreens in somehow (though as the Pebble watch shows, they can also work reasonably well without touch). If you owned one of the small, square sixth-generation iPod Nanos, you may have already gotten a glimpse into this future. These devices had touchscreens, a limited selection of apps, and were easy to wear around your wrist in place of a watch, provided you had the right strap.

Tiny touchscreens like the sixth-generation iPod Nano could suggest a direction for future smart watches.
Jacqui Cheng

Touch really is working its way into just about everything with a screen, whether it's enabling brand-new experiences or just augmenting old ones. And that's the present of touch technology: it's successful, it's widespread to the point of near-ubiquity, and it continues to change what we expect from our devices. In our next article, the third and last in the series, we'll be looking precisely at those expectations as we dive further into the future. We'll explore how new technological advancements will continue to shape tomorrow's touch devices, and we'll look at how software will continue evolving to support this new hardware.

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