colin@pdn.UUCP (Colin Kendall) (06/21/88)
Some time ago I tried to generate enthusiasm for the use of the Dvorak
keyboard among the members of my project team. A major objection, raised by
several members, was that the project would be doomed to failure without total
immersion; i.e., unless all keyboards in the area could be converted.
Due to my experience in rapidly switching among various computers, operating
systems, editors, etc., I felt that having one more variable in the
environment would not be an insurmountable problem, and so I
pig-headedly plunged ahead, setting things up so I could use Dvorak
while in Smalltalk, and QWERTY elsewhere.
My experience was that the "muscular memory" used in typing operates
at some deeper or more primitive level than the normal memory used
in determining which command to use to copy a file, etc.
It seems that when I want to type an 's', the events which cause
the 's' to be struck occur almost without thinking, or certainly
without any conscious attempt at recall. And it is almost
impossible to reprogram this except over a long period.
If I typed exclusively in Dvorak for an hour, I rapidly got
faster and more confident, and made fewer errors; but if I then
switched back to QWERTY, I was slower than a turtle; and vice versa.
I estimate that before I started the experiment, I could type about
50 wpm. After a month of switching back and forth, I could type about
15 wpm in Dvorak, and only 30 wpm in QWERTY!
I have therefore given up on Dvorak for now; I would certainly like
to return to it, but only with total immersion.
An interesting side effect is that the experiment seems to have
adversely affected my ability to play the piano.
The experience has deepened my respect for muscular memory, and increased
my desire to try to incorporate "pie menus" into the product we are
developing. (With pie menus, the item chosen depends on the direction in
which the cursor is moved from some central point. Studies have shown that
after a little practice, users of these menus no longer need to
look at the screen while making menu selections, even complicated
cascades of selections!)
--
Colin Kendall Paradyne Corporation
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Phone: (813) 530-8697 8550 Ulmerton Road, PO Box 2826
Largo, FL 33294-2826norman@sdics.ucsd.EDU (Donald A. Norman) (06/25/88)
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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