Newsgroups: comp.human-factors
From: ematias@dgp.toronto.edu (Edgar Matias)
Subject: Bill Buxton's reply to the recent summary on trackballs vs. mice
Organization: CSRI, University of Toronto
Date: 31 Dec 92 21:57:23 GMT


The author of the following message (Bill Buxton) asked me to
post this article for him.  It's his reply to the recently posted
summary on comp.human-factors readers' opinions of trackballs vs. mice.
Pretty interesting stuff...
 
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From willy Thu Dec 31 11:38:35 1992
From:   William Buxton <willy>
To:     davidk@mcil.comm.mot.com
Subject: Trackbals vs mice
Cc:     ematias, willy

I just read your digest on mice vs. trackballs.  It was as interesting as
much for what it didn't say as for what it did.  First, it is interesting
how many people responded who were in the field of HCI and UI design, and
yet only one cited any formal literature (gladly, some work from our lab).
I wonder if this is indicative of a failure of the science being done in
this area to address the needs of designers, or a lack of knowledge of
the literature by practitioners.  To be fair, you were asking for personal
experiences, not literature reviews.

But let's quickly address a few things left out:

1. Speaking about "trackballs" vs "mice" is like comparing "vegetables" vs
"fruit."  Why?  Because there are so many variations of each.  Let's just
look at some of the larger dimensions of variation among trackballs:

        - size
        - inertia
        - which hand (dominant or non-dominant)
        - finger or thumb operated
        - placement of buttons
        - location (central as in Powerbook vs side)
        - anchored (fixed position) or hand-held (like video game controller)
        - task: pointing vs selection vs dragging vs drawing
        - age, ability/disabiity of user
        - etc

One will see as much variation within the class of trackballs themselves as
between some specific cases of mouse vs trackball.  In short, what I'm saying
is that it is very important to discuss these things at a much finer grain
of analysis.

2. In discussing such things, I continue to wonder why people tend to compare
one device vs. another.  With musical instruments, for example, this isn't the
case.  If I invent a new instrument it is not to displace an existing one,
it is to compliment it.  So should it be with input devices.  For each one
there is some task for which it is best and some for which it is worst.
(Each condition may be more than a little obscure, admitedly.)  Our real task
is to find out what the idiom of each is, and reveal the properties of task,
user and context in which each is suited/ill-suited.  Of this kind of work,
there is too little.  This is the direction that I believe such discussions
must go.

3. As an example of seeing the trackball/mouse question in a new light, simply
by changing a few things, let me give you my favorite example. Instead of
having the two in competition, why not use them together.  Consider using your
mouse as usual in your dominant hand.  In addition, have a trackball on the
other side used by your non-dominant hand.  The mouse is used for primary
point/select/drag tasks.  The trackball is used to scroll your window, i.e.,
to navigate.

With this arragement, a few interesting things emerge.  First, you no longer
have to use your mouse to futz around with the scroll bar/arrow widgets.
Second, a little practice will make clear that the device hand mapping is
much better than, say, two mice, two trackballs, or the mouse and trackball
reversed.

This is how I read my mail, etc. on my powerbook:  with a mouse AND a
trackball.  This is available to an Mac user by getting Michael Chen's
"Trackball-scroller Init" off of the Apple Science CD Vol 1.  If you
want a bit more fuller discussion of such 2-handed usage, then some of
the underlying experimentation can be found in:

Buxton, W.  & Myers,  B.  (1986).  A  study  in  two-handed  input.
Proceedings of CHI '86, 321-326.

A less formal discussion that nevertheless looks at the issue in the context
of an application can be found in:

Buxton,  W. (1990).  The Natural Language of Interaction:  A Perspective on
Non-Verbal Dialogues.  In Laurel, B. (Ed.).  The Art of Human-Computer
Interface Design,  Reading, MA:  Addison-Wesley.  405-416.

Some of the general issues involved in making comparisons among devices are
discussed in the following 2 papers:

Buxton, W. (1986) There's More to Interaction than  Meets  the  Eye: Some
Issues  in Manual Input.  In Norman, D. A. and Draper, S. W. (Eds.), (1986),
User Centered System Design:  New  Perspectives  on Human-Computer Interaction.
Lawrence Erlbaum Associates, Hillsdale, New Jersey, 319-337.

Buxton, W. (1983). Lexical and  Pragmatic  Considerations  of  Input
Structures.  Computer Graphics 17 (1), 31-37.

I'm not putting this forward as a means of promoting my own work.  Rather,
there is very little published on input compared, for example, to displays,
and what there is is hard to sort through.

There is a lot of activity on input here at the University of Toronto's
Input Research Group, and we would be glad to distribute digests of our
work to interested parties.

Cheers & Happy New year.

William Buxton
University of Toronto & Xerox PARC
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Edgar
-- 
Edgar Matias
Input Research Group
University of Toronto
--
I speak for no one...
Newsgroups: comp.human-factors