In my last post, I set the stage for a multi-post look at the future of smart product interfaces. To recap briefly, I believe that interface technology is at a really interesting point, where older approaches such as the keyboard and mouse are being superseded by new possibilities. However, there are lots of options and I thought it would be worth looking at some of the major contenders to understand the pros and cons of each and see if any look particularly well-suited to become as ubiquitous as keyboards were. In today’s post, I look at the simplest class: touch-based systems.
The simplest touch-based interface is a physical button, whether used as an on/off switch, a part of a keyboard, or otherwise. They are simple, cheap, reliable and well-understood, both by users and system designers. However, they are static and immutable – you can’t make them disappear when you don’t need them and you can’t really change how they look or what they do. They offer very limited versatility and are often not the cleanest or most elegant solution.
At the next level up in sophistication are discrete touch sensors (usually capacitive) – picture a lamp with no switch that you can touch anywhere to actuate. The use of capacitive and other types of touch sensors can liberate designers from some button-placement restrictions but that is about the extent of the benefits. Most of these sensors are binary (either on or off; no other states) and again offer limited versatility as their function cannot easily be changed during operation.
Continuing the trend towards increasing complexity brings us to touch screens, which are essentially just an array of touch sensors overlaid on a display. The monumental benefit of this approach is the versatility enabled by the screen – the same “button” (or area of the screen) can have an infinite number of purposes if the system merely changes what the user sees. However, touch screens have their limitations as well – their inherent 2D-ness requires a level of abstraction to map the real, 3D world and they have some proximity restrictions (the user has to be close enough to physically touch them).
The smart phone revolution of the last few years has given us a powerful illustration of how useful and popular touch screens can become and I think that they are by far the most powerful interface currently available at a production level of sophistication and usability. However, in my next post I will start getting into some new technologies that are quickly advancing and could supplant touch screens in the not-too-distant future.