UI usability for 4 year old (was Re: Call for Papers/Talks/Ideas!)

[Mitch Bradley]

John R. Hogerhuis wrote:
> On Sun, Mar 23, 2008 at 9:28 PM, Mitch Bradley <wmb at laptop.org> wrote:
>
> <snip>
>
>   
>>  In any case, the left and right panels can't sense fingertip pressure -
>>  you would have to use a fingernail, and that would override the signal
>>  from capacitive sensor.
>>
>>
>>     
>
> OK, thanks. So that idea won't fly. Holding down a keyboard key to
> paint or a mode change (up/down)  on button press would work. Could
> up/down be done by pressure on the center pad? As in, move the cursor
> around with your finger, when you want to start dragging, push hard.
> When you want to stop dragging, push hard again. Then she could work
> it with only one finger.
>   

In principle, that would work, but in practice, the difficulty of 
calibrating the touchpad might make it less reliable than we would 
like.  The XO is smaller and has less metal than an ordinary laptop, so 
its touchpad is rather sensitive to calibration problems on the 
capacitive sensor, which depends on the ratio of touchpad-to-finger vs 
touchpad-to-external-ground capacitance.

> BTW, for whoever maintains Paint activity: this is the key activity
> for my 4 year old. It's one of the few where the application is age
> appropriate since she can mostly get by with the icons (she can read
> and write several words now but not enough of the right ones to come
> close to working, say the Record application). The other activities
> she uses are Write and Record. Write, she just types names and words
> she knows, and makes patterns with letters. Record, she enjoys but
> needs my help to use at all because of the wordy UI.
>
> -- John.
>