be represented as a green branch
so when the use of a tool
requires moderate effort
the branch turns yellow
and with high effort, red
we (mentally) trim a branch segment
with startingpoint where the tool-user
conceives a subgoal
and with endpoint
where that subgoal is achieved
the yellow-and-redder this segment appears
the lower we rate the
interface design
for this subgoal
(less common subgoals
are allowed to score redly
but the most common
need careful greening)
as the tool-user proceeds
the hi-tech tool
a pc
is streaming music
(say, via Pandora)
but the stone-age digital format (mp3)
frequently changes volume
(sometimes dramatically)
demanding quick response from the user
maybe a dedicated hardware analogue
dial on the cpu box
or on the monitor, or keyboard, or mouse
maybe a custom keyboard macro
or maybe a yellow-branch trip to the Windows tray
and an orange-branch mind-and-eye-squinch
to find the volume-icon
and an orange-red mouse-targetting of that tiny icon
followed by a retargetting on the popup control's slider
and a careful slide
a listening
a re-adjust
and finally a dismissal of the control
(o billg have mercy on us poor users)
since the pc's audio channel
is normally uncorrelated with the desktop's top app
that app needs to afford it
n square-pixels
of dedicated screen real-estate
preferably in a corner of the screen
where the mouse can be 'thrown' in a Fitt
and since volume is the most commonly required tweak
the mousewheel should become a volume control
whenever it hovers near that corner
(perhaps the lower right
is currently least-used?)
