From: db3l@ans.net (David Bolen)
Subject: Re: Typing, reaction times, and users (was Re: GUIs Considered Harmful)
Date: Fri, 11 Sep 1992 15:11:58 GMT
	<1992Sep08.215240.49778@ans.net> <3258@isgtec.isgtec.com>
Organization: Advanced Network & Services, Inc. - Elmsford, NY
Followup-To: comp.human-factors

In article <3258@isgtec.isgtec.com> mike@isgtec.com (Mike Sellers) writes:

>Second, typing as a learned skill is different from a cognitive behavior.
>Minimum reaction times where attention and cognition (decision) are involved
>are _at best_ about 0.3 seconds for very simple tasks ("press the button if
>the second letter you see is the lowercase version of the first letter you
>see").  This RT decreases as the cognitive loop is removed, down to a
>lower limit of around one action per 0.075 second; (...)
> (...)
>Expert typing does not require conscious attention, just as signing your
>name with a pen does not (once you're beyond elementary school, anyway :-) ).
>When you type at speed, you do not think about which fingers are moving
>where, as they do not require the conscious control that they do for a task
>requiring attention and decision.  Thus, reaction times of about 1 second
>are, contrary to the first poster's assertion, at least average if not
>slightly above average for that kind of task.

Well, this does raise an interesting point from my view - ideally, to
improve efficiency, you'd like to remove the cognition component as much as
possible.  One way I would think it could be done would be to make as many
decisions up front as you could, and then let a learned skill actually
accomplish the goal of the decisions that were made.  Here's where I tend
to think that the keyboard can be a big win over the mouse (or auxiliary
input device) as well as GUIs in general.

For one example, in my personal experience, I believe that I have actually
learned to touch-type much of the emacs basic command set, in terms of
performing editing functions almost at full touch typing rates.  When
working on a document (or code, or whatever), I often find myself thinking
at a higher level than the keys that need to be hit to accomplish a task.
Instead, I am just thinking about the task itself, such as "delete line",
"move up", or even start new function declaration "foo".  So I believe that
I still have a decision step at the beginning of the process, but that I
have removed that delay from much of the actual operation, even if the
operation involves several different keystrokes.

The point is that I don't think I could ever achieve that level of
performance if a mouse or GUI (ie: menus) in use.  There would always be
some visual feedback that had to be interpreted, and I would never really
be able to remove the decisions being made at each stage of the operation.
The act of interacting with the GUI would interrupt my ability to use my
learned skill (typing) to speed the completion of my task.

Or, as an alternative example (and at the risk of starting a word
processing war), say I was using a WYSIWYG word processor under a GUI
system, versus emacs editing a TeX document.  In the former case,
boldfacing some text would probably necessitate selecting something with
the mouse or at least hitting a button or menu option.  With TeX, I would
have to type additional prefix characters ("{\bf") and an additional suffix
character ("}").  However, in the TeX case, once I decide on boldface, and
therefore what characters to use, they just become part of the stream I am
touch-typing, and only the initial decision is involved.  In fact, I might
even postulate that since I'm pretty much on automatic while typing the
text up to this point, I could even overlap the decision to use boldface
with some of my previous typing, resulting in no net additional delay by
the need to use boldface.  As before, with the GUI, additional coordination
and visual feedback (not to mention moving my hands) is involved, and
should always be less efficient, no?  (assuming maximum efficiency in both
cases)

>| >On the other hand, if you really do type "well over" 100wpm then you are
>| >at the far end of the typing-speed spectrum.  Given this, your needs and
>| >abilities do not conform to the needs and abilities of the vast majority 
>| >of computer users; you cannot judge them by looking at yourself.
>| 
>| Ok, maybe I'll buy that.  But that doesn't invalidate either of our thoughts
>| on the use of rodents (I happen to strongly agree with der Mouse (is that a
>| proper name?) in this area), does it?
>
>Not for users like you, no.  However, you are a definite minority, and are
>unlikely to be the focus user of any major software products.

I guess I feel that's unfortunate.  Not so much that I personally am not a
user likely to be focused on for a major product, but that it seems that
this performance gain can be seem by a larger number of people - even those
that aren't so far up the typing curve.

I certainly haven't done scientific studies (and so will defer to those
that have), but just when interacting with other users (who mostly work
at average typing speeds),  I have often noticed that they seem to have
"learned" basic operations of many of the programs they use, in much the
same way that I've learned editing sequences in emacs.  They'll whip
through a set of commands/options using the keyboard without ever even
looking at the intermediate, or even sometimes final, result.

So I would think that even the average user can benefit from being able to
take advantage of this learning process, which seems to apply better to a
keyboard interface (in terms of how much efficiency can be gained) than to
a mouse or GUI interface (where you are always limited by visual
interaction).

>Multiple channels of input should certainly be supplied, including text 
>shortcuts if the users are at all likely to employ the keyboard.  This
>does not invalidate the use of the mouse for many other users.

Well, we definitely agree on this point.  Maybe I came into the discussion
at a slightly wrong point, as I don't want to see the mouse disappear, but
I would want to fight to make sure that it's not the only way that
applications allow people to interact.

One of my biggest complaints back when the Macintosh first came out was
that its applications were heavily dependent on the mouse.  It's gotten
better in recent years, but it used to be that most if not all of an
application's functions had no keyboard equivalent, which to me especially
(although I do think it also applies to an average user) was a horrible
design choice.  Especially with anything that involved text (or as you
said, applications likely to employ the keyboard), I felt like I was being
forced to work slower than was possible, and it got annoying.

--
-- David
--
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