byard@dca-ems (04/10/83)
From: Larry Byard (WSE-EUR) <byard at dca-ems> I am on a business trip at present and I7 stuck with a TI 700 instead of my CPT word processor so thid will be short... I used the Navy Tactical Data System for three years. It had a track ball which worked qyite well, with practice. And by the way it had buttone, right in front of the ball. I have also used the mouse ont Xerox's Star Work Station. To me, the mouse is the winner and it is also much easier to learn. Larry
liberte@uiucdcs.UUCP (05/29/84)
#N:uiucdcs:13900009:000:3139
uiucdcs!liberte May 28 20:09:00 1984
First, to discredit myself, I have not read most of the studies comparing
trackballs to mice and other input devices. Also, I have not used a mouse
more than in a demo. But I have used trackballs for many hours, on
video games. To some, that would discredit me further. About the only
games I play use trackballs - Centipede and Crystal Castles, in particular.
My feeling is that the trackball offers advantages over the mouse that
have not been fully considered. I will also list the disadvantages.
First the similarities:
1. They are both pointing devices, as are many input devices.
2. They can both operate with proportional body movement.
- a more sensitive trackball and/or larger scale cursor motion can
give one roll per screen without the need to spin the ball.
The trackball is better because:
1. The trackball stays in one place
- no clear space on the desk is needed.
- it can be operated without looking at it, more so than for the mouse.
- it can be located close to the keyboard for faster access.
- mouse requires cleaner, more secure environment, whereas
trackballs are suitable for video games even.
2. The trackball is omni-positional
- that is, the cursor can be located anywhere on the screen whereas the
mouse cursor is usually mapped from the mouse position. This allows
cursor jumping and returning without large movements of the arm.
- wrap-around is reasonable with the infinite range of the trackball.
- stopping at window edges and ignoring further motion is possible.
3. Scale of cursor motion can be adjusted
- very small trackball movements may correspond to large cursor motions
and large trackball movements may correspond to small cursor motions.
- one can also adjust mouse cursor motion scale, but the mouse to
cursor mapping is shifted. Occasionally one must adjust the mouse.
4. A third dimension of trackball rotation in-place is possible.
- screen object translation and rotation can be combined in one device.
- pressure sensitivity may be added for another, short dimension.
The mouse is better because:
1. The mouse has more direct mapping between arm motion and cursor motion.
- consistency has an effect of simplicity and ease of use.
Jumping of trackball cursor can be confusing.
- the pointing effect of the arm motion may map better in the brain
than the rolling of a trackball across fingers and palm.
2. Buttons are easily used on mouse.
- single arm interaction is possible.
- trackball would usually require two arm interaction.
3. It is nice to have a clear space on your desk.
So what am I missing? I have found the trackball to be enjoyable and
easy to use. Part of that is due the well designed games I used it
with. But the trackball would seem to have much greater application
given finer resolution trackballs and appropriately designed software.
Your comments? I will summarize whatever you mail, if you wish.
Daniel LaLiberte (ihnp4!uiucdcs!liberte)
U of Illinois, Urbana-Champaign, Computer Science
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