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iPhone Antenna Problems Pose Alternative Interface Design Questions

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The iPhone4G loses reception if users hold the phone at its lower left corner. A problem solved, according to Steve Jobs, by "don't hold it that way;" or by using an iPhone case accessory. This is a trivial problem, but it raises again the issue of an increasing gap between technology and the interfaces necessary to use that technology. Not yet reported, but easy to anticipate, the higher resolution of the iPhone4 allows smaller controls to be packed closer together, creating huge problems if you have large fingers.

Hardware engineers continue to pack more processing power into smaller devices but the real barrier to increasing miniaturization arises from human abilities to interact with them. The mobile phone is where this conflict is most obvious. As Patrick Baudisch of Hasso Plattner Institute (and formerly at Microsoft Research) noted earlier this year:

There is a single true computation platform for the masses today. It is not the PC and not One Laptop Per Child. It is the mobile phone - by orders of magnitude. This is the exciting and promising reality we need to design for.

Interface problems include more than large fingers and skin conductance interfering with an antenna; you cannot use skills, like touch typing, on a phone, touch control is far less precise than even a mouse cursor, and you cannot use available interfaces in certain contexts (like touching while driving).

Some problems and potential solutions: (excerpted from Communications of the ACM, Feb. 2010)

  • Large fingers. Baudisch worked on a technology called NanoTouch that allows the mobile device to appear as if translucent and moves the touch interface to the rear of the device, preventing a finger tip from obscuring the interface. Baudisch is also working on a project called RidgePad that detects both touch area and fingerprint ridges within that area to more precisely calibrate the input and "double the accuracy of today's touch technology."
  • Limited surface area. Chris Harrison, a graduate student at Carnegie Mellon University, is working on the using the surface area upon which a mobile device rests, a tabletop for example, to increase the effective surface area available for input (a technology he calls Scratch Input). Using a small acoustic microphone in the device, vibrations caused by a user scratching or tapping on a tabletop are detected and used as input signals. An example would be scraping your fingernail across the table top to increase or decrease volume on your media player. Harrison is also working with others on the use of deformable surfaces to create multi-touch simulations of buttons, sliders, and keypads.
  • Touch typing, still the fastest way to enter data into a computer. Several commercial products are available that offer external keyboards and even projection of virtual keyboards onto any flat surface.
  • Gross accuracy of available touch screens. Ilya Rosenberg and Ken Perlin, at New York University, have developed an interpolating force-sensitive resistance (ISFR)technology that samples signals from overlapping areas on a touch screen to increase accuracy more than 25 times the density of the sensing array itself.

In the future, the interface might be disassociated from the device entirely and moved into our bodies. Visual displays incorporated into the retina of our eyes, direct conductance "speakers" implanted in our ears, and haptic sensors incorporated into our fingertips.

Ultimately, the 'impedance mismatch' problem between our technology interfaces and human users will be decided more by the users than the technologists. Just as a new 'language' was invented to circumvent the limitation imposed of a phone number/letter pad (e.g. "c u l8tr"), users will find a way. It would benefit technologists to take into account the ingenuity of users and the affects of culture and everyday experience as both a constraint and an inspiration for design. It is inconceivable that in all the months leading to the release of the iPhone4G that none of the engineers ever held the phone at the lower left corner and experienced the loss of signal being reported by users. It is equally inconceivable that Apple engineers and designers did not expect that holding the phone in such a manner would not be a common experience among users. And yet - by virtue of the fact that this was not addressed in the antenna design - it appears that the inconceivable did in fact occur.

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Community comments

  • Not really inconceivable

    by Robert Sullivan,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    It's perhaps surprising this issue wasn't caught, but certainly not inconceivable. As someone once told me, the real testers are your regular users, not system testers, or acceptance testers. I was given an app and told it was ready for production. Fortunately we deployed it on a "test" production server, a soft launch. A user kicked the tires and said there was an extra tab when she moved through the form. The system tester had seen this, but used the mouse mostly, and never reported it. But when you are processing 100s of forms per day, you don't use a mouse since it's too slow, and an extra tab will slow you down or throw you off immensely.

    I agree they should have spent more time with different test scenarios such as "does antenna work when I hold it in top right corner? top left?" etc, given that this was a new change. But you also have to understand the heightened development pace in getting a major piece of hardware and software out like this, in comparison, it would seem this is a minor issue given some of the considerable issues with other mobile devices, showstopper issues such as battery issues, etc.

    Further, one of the advantages of a design like the iphone is that the interface is that there is that much less "impedance mismatch" than other interfaces, like mouse or ball driven ones on the blackberry. Waving your finger is much more natural, so I mostly disagree with this article. For example, one of the main examples, the smaller keyboard supported, is almost a non-issue due to the iPhone design. On a blackberry, you have tiny buttons, that seems problematic. On the iPhone, developers are free to make the buttons any size, or design an entirely new interface, since these are software buttons. There is no limit.

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