Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!nosc!ucsd!sdics!norman
From: norman@sdics.ucsd.EDU (Donald A. Norman)
Newsgroups: comp.cog-eng
Subject: Re: A Dvorak keyboard experiment
Keywords: Dvorak thumbs keyboard
Message-ID: <554@sdics.ucsd.EDU>
Date: 24 Jun 88 17:10:56 GMT
References: <3535@pdn.UUCP>
Reply-To: norman@sdics.UUCP (Donald A. Norman)
Organization: UC San Diego Institute for Cognitive Science
Lines: 37

The reports of the Dvorak-qwerty switching experiment are interesting
and consistent with what I would expect (as an experimental
psychologist).  This is NOT what Dvorak enthusiasts claim, however:
they claim that one can switch readily among keyboards.  I believe the
current reports of difficulties.

Do not get too excited about the advantages of "motor memory."
Nothing special about "motor."  The same phenomenon works with
anything that is over-learned, over-practiced.  Such skills become
automated and, thereby, sub-conscious.  These skills can be done with
minimal interference to other ongoing tasks, with little or no
conscious attention, and with great precision and speed.  And once a
skill reaches this level of automation, it is very difficult to
change.

PIE MENUS:

I suspect that pie-menus are good things, but not because they are
motor.  Rather, they are good because items appear in a consistent
place and it is easy for a single movement to select them.

Regular pop-up or pull-down menus may be consistent, but visual
attention is needed to find the desired target.  Of course, pie menus
only work with a limited number of entries (so that the selection
stroke does not require high angular precision).  I predict that if
you add too many entries, they will require visual attention just like
regular menus.

Don Norman


Donald A. Norman
Institute for Cognitive Science C-015
University of California, San Diego
La Jolla, California 92093
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