[linux-audio-dev] Knobs, the reply

[Tim Hockin]

On Thu, Jun 10, 2004 at 08:02:48PM +0200, Thorsten Wilms wrote:
> > When you move the mouse slowly, you get very fine control.  When you move
> > it faster, the control gets coarser.   So you can move a knob from 0.0 to
> > 1.0 quickly with a fast mouse gesture, or you can move it from 0.5 to 0.6
> > very slowly.
> 
> Thanks. Sounds like trouble with controlabilty/predictability to me.

It is unpredictable.  I don't much care for it as a UI feature.  It is
very hard for me to stay below the 'fine-grain' speed limit.

> > I'm still going to put my bet on linear.  If you do a usability study of
> > linear vs radial, I bet linear will be more obvious and easy to control.
> > And you will not convince me otherwise until I see a usability test done
> > with non-LAD users :)
> 
> Maybe linear is easier to handle, but the usual knob graphics are 
> still misleading (you can't tell me something round with clear center 
> hints at linear movement, even if the real world metaphor is left out).

I think that your frontal lobe is saying "knobs are round, move the mouse
around them" but I still believe that your hand will find it more
intuitive and correct to move the mouse in one direction - up and down.

> > This is such a bad idea, unless the control is an X/Y control to start
> > with.
> 
> No, I did not mean 2 axes for one widget. Only that a linear widget has 
> to indicate it's direction even before interaction happens, and that it 
> makes sense to use vertical for volume and horizonal for pan in the 
> same interface.

OH!  Hrrm, yes, well.  I see the point, but I don't think it will work.
Differing semantics for similar-looking widget is the worst of all possible
choices.