Touchscreens: the most terrible phone HID in history?
Well, I thought that I would get used to it, but after one month spent trying, I have to admit that I simply can’t understand why touchscreen phones are so popular nowadays. Once I’ve completed my review of that bada phone which I’ve bought with my new contract, I’m probably putting my SIM card back in my E63 and using it till its death, then buying another button-based phone, and so on until there’s no button phone left or a saner alternative has emerged.
No matter how hard I try to be open-minded, I can’t help but noticing every single day how bad the touchscreen HID is at a fundamental level, at least for my usage patterns. Let’s explore the various dimensions of what makes the touchscreen a massive UI fail for me…
It all begins with the loss of the ability to hover things.
Any button- or mouse-based graphical interface features the simple, seemingly unimportant ability to put the pointer on an on-screen object without interacting with it. Modern GUIs also commonly associate visual feedback with this action, be it changing the pointer’s shape or the pointed object’s color, to help the user figure out what exactly he’s currently pointing on the screen.
This ability for the user to know what he’s going to do before actually doing it is critical in error or mistake prevention, which is a major component of usability.
Even modern pen-based interfaces have managed to feature the hovering action, even though implementing it on such an interface is a technical challenge. All Wacom tablets allow you to put the pen a few millimeters above the tablet in order to move the mouse around without actually clicking anything.
But finger-based touchscreen interfaces fail to do that.
The last attempt at implementing a hovering action on a touchscreen can be seen in RIM’s Blackberry Storm, with its clickable screen. However, the button was way too hard for everyday usage on tasks like typing to be envisionable. And what’s more, it didn’t solve another fundamental problem with touchscreens: that the human finger is not transparent.
This is the second thing which makes the touchscreen interface so poor as far as feedback is concerned. And this is not a trivial problem. On a touchscreen, the area which you’re interacting with, which is obviously the most important on the screen, is hidden by your finger for the duration of the interaction.
Apart from causing unnecessary constant finger movement (to get the finger on the screen for interaction and off the screen for visibility), this means that you can’t adjust your tapping movement in real time as you’re doing it. By using a touchscreen, you lose the whole eye-hand feedback loop for some blind and imprecise way of moving your finger.
And for the disaster to be complete, modern touchscreens are also perfectly flat. Haptic feedback being gone in the name of coolness.
Apart from the fact that the lack of haptic feedback increases the difficulty of making precise movements even further, just wonder: what could be better coupled with a small screen like a cellphone’s, that begs for efficient use of the available space, than a big, greasy finger? That would undoubtedly be part of a big greasy finger. Because, as you probably know, only a part of your finger is touching the screen and being registered by the hardware. The thing is, depending on how your finger hits the screen (inclination, strength…), it won’t be the *same* part of your finger that will be registered by the hardware. Buttons have addressed this problem for ages by adopting an embossed design which allows buttons to be “felt” and makes sure that it’s the whole finger’s movement which matters. However, touchscreens don’t have that either. Hence the disaster that virtual keyboards are as soon as you get outside of the limits of their T9-ish prediction and auto-correction algorithms.
So okay, you might say, touchscreens are a totally imprecise interface without any sort of sensorial feedback, having even less than the mouse which is often criticized for being a peripheral that requires some learning to be used. Making them even barely usable by compensating their imprecision requires making gigantic-sized buttons, which is a totally impractical option on many hardware which we put touchscreens on, phones especially. But they bring the key benefits of intuitivity and flexibility, right?
Touchscreens are less flexible than equivalent button-, mouse-, or pen-driven interfaces, because they can display much less content due to their inefficient use of the available space. You commonly see much more power on button-driven Symbian apps than on the average iPhone app which does generally exactly one thing (emitting noises, turning the screen white…). That’s not because all iOS devs are incompetent, it’s just that they realize how limited the touchscreen interface truly is, how little they can put on the screen before making their app feel complicated and difficult to use.
And as for the “intuitive” side of thing, one has to remember that part of usability it is about having the right tool for the right job and making the frequently used functions of a tool easily available. Let’s assume that you know how a landline phone works, and want to call some number. With an average button-based cellphone ($70), you’ve got the familiar alphanumeric keyboard, on which you type your number and press the calling button. With an iPhone ($700), which is commonly invoked as the paramount of touchscreen usability, all you’ve got is a big, messy application grid, and you’re supposed to find out what is used to make calls by yourself. You basically have to figure out how everything in the UI works before being able to do something as basic as making a call.
This is just one of the many ways most touchscreen devices totally fail to optimize the common case. Another one being that although a cellphone is mostly used for calling and texting on the average, touchscreen cellphones still offer primitive text input methods.
Oh, well, at least you can see more details of fart apps’ logos on this 4″ screen. Displays a good picture of how hygienic touchscreens are.
I simply can’t understand how this terrible piece of HID that touchscreens are could become so popular. Of course, this doesn’t matter, as I’ll have to optimize for it anyway. But still… WTF ?