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From: barmar@think.COM (Barry Margolin)
Newsgroups: comp.sys.mac,comp.windows.misc
Subject: Re: 2 button mouse
Message-ID: <17702@think.UUCP>
Date: 10 Mar 88 02:08:51 GMT
References: <4129@hoptoad.uucp> <283@rhesus.primate.wisc.edu> <1710@ssc-vax.UUCP> <241@eos.UUCP> <1735@ssc-vax.UUCP> <5674@cit-vax.Caltech.Edu> <7481@agate.BERKELEY.EDU> <7602@apple.Apple.Com>
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Reply-To: barmar@fafnir.think.com.UUCP (Barry Margolin)
Organization: Thinking Machines Corporation, Cambridge, MA
Lines: 50
Keywords: window human computer interface


This whole argument about the number of buttons on the mouse is silly.
The Mac already has a virtual 16-button mouse.  Where are all those
other buttons?  One of them is on the mouse itself: you can
double-click (and some applications even make use of triple-clicking).
The rest of them are on the keyboard: you can hold down Shift,
Command, or Alt (and Control, on the new keyboards?) in order to
modify the meaning of a click.  Thus there are eight combinations of
modifier keys and either click or double-click, making sixteen ways to
click the mouse.

I've used 3-button systems (Symbolics Lisp Machines and Sun
Workstations) and 1-button Macs; I find them all relatively easy to
use, but I have a good memory for arbitrary keystrokes (and Symbolics
machines have a line at the bottom of the screen that lists what all
the mouse clicks currently do).  I also taught my parents, who are
completely computer illiterate, how to use the Mac.  In this case, I
am very glad that it only has one button, as it was hard enough
teaching them how to use the menus, and double-clicking was a major
achievement.  I can just imagine them calling me up at night to ask
whether they are supposed to push the left button or the right button
to use the menu.

The Mac user interface is designed not to tax the memory of extremely
unsophisticated users.  This is the reason for the one button and the
constant menu bar.  Unsophisticated users should be able to do
everything they want without ever having to double-click or click
while holding a modifier key.  MacWrite is a good example of this
philosophy: double-click lets you select a word, but this is just a
shortcut for click/drag; shift-click lets you select a big region
without having to drag across the entire thing.  MacPaint is a bad
example: you need to shift-click/drag in order get constrained motion.

A good analogy for all this is Emacs-style text editors compared to
dedicated word processors.  Word processors generally use arrow keys
to move around and have lots of specialized function keys with
appropriate labels; they are easy for computer-illiterate secretaries
to learn.  Emacs is based on memorizing only-somewhat-mnemonic control
sequences.  We power users tend to find the word processors extremely
limiting; there's a dozen or two function keys, and that's all you can
do.  But a computer neophyte would find Emacs completely overwhelming.
Everywhere I've been where Emacs is used, I've seen lots of Emacs
wallcharts pasted above terminals.  Apple didn't want people to have
to post MacWrite wallcharts.

Barry Margolin
Thinking Machines Corp.

barmar@think.com
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