[IxDA Discuss] "Interface-Free" Interface

[Alan Wexelblat]

I can't find the references at this moment (they're on this ancient
paper medium somewhere in my home office filing cabinet) but back in
the late 80s the military went through a fad of touchscreen
interfaces.  They were found to be highly error-prone and fatiguing.

Error sources include:
- size of the pointing device (fingertip vs cursor)
- selection with the finger obscures the thing you're trying to select
- uncertainty on feedback.  The combination of physical feedback (does
the screen flex in response to pressure?  If so how much and how does
the user correlate that feedback with visual changes?) proved
difficult for some users.
- dirt and oils from human hands tended to introduce errors and
obscure displays after extended use.

Fatigue sources included:
- necesity for operators to hold their arms up
- requirement to reach and retract arm on each completed interaction
- positioning of the screen for touch required operators to change
their head/body positions
- operators tended to crane their necks sideways to try and confirm a
touch that was full or partially blocked by their fingertips.

The tasks used were very similar to the original "Put That There"
gestural interface, which is why I got interested in the research (I
did my MS on gesture). The military operators used the touch screens
in 1, 2, 4 and 8 hour shifts that matched their normal work schedules.
 Even a one-hour shift was perceived as fatiguing.  This leads me to
believe that touch interfaces are fine for casual interaction over
short periods, but not really suitable for extended work.

On 10/29/06, Dan Saffer <dan at odannyboy.com> wrote:
> "Jeff Han demonstrates—for the first time publicly—his intuitive,
> "interface-free," touch-driven computer screen, which can be
> manipulated intuitively with the fingertips, and responds to varying
> levels of pressure."
>
> http://ted.com/tedtalks/tedtalksplayer.cfm?key=j_han&flashEnabled=1
>
> Just because an interface is [arguably] easy to use, doesn't mean
> it's interface free. While I think this is a really need use of the Z-
> axis and a gestural interface, I'm wondering about its limitations
> for daily use. Could I type on a touch-screen keypad all day, for
> instance? How would MS Office for instance (not to mention Adobe
> products) get translated into this mouse-less OS?