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From: dak1@cbnewsi.att.com (darren.a.kall)
Newsgroups: comp.cog-eng
Subject: Re: Right Hand Rule
Summary: more questions
Message-ID: <1990Aug2.165035.23073@cbnewsi.att.com>
Date: 2 Aug 90 16:50:35 GMT
References: <1990Jul31.193057.4434@pdn.paradyne.com> <9967@hubcap.clemson.edu>
Organization: AT&T Bell Laboratories
Lines: 38

In article <9967@hubcap.clemson.edu>, manne@hubcap.clemson.edu (Vijay Chachra) writes:
> 
> subjects from different parts of the world. An informal discussion in my
> Human Factors Engineering class resulted in mixed preferences. The
> reasons for not accepting the rule universally could be as follows:
> 
> a. It depends on the application.
> b. It depends on whether the controls are to be operated by both hands
>    or one hand.
> c. There is a definite difference in preference between left-handed and
>    right-handed persons.
> 
> Note: Would like to hear comments from fellow netters.

A non-intuitive addition that I ran into is a person's cognitive expectation
for performance and linguistic expression being different. I would like
to see it tested if it hasn't been already to evaluate its strength and 
importance.I will try to clarify with an example and a poor drawing.

	decrease . . . . . . . increase
	               ^

Say you have a slide control with two ends, decrease and increase (or
negative and positive, less and more, off or on, etc) and the user's
task is to increase the quantity of some value.  The users have an
expectation that the physical action of moving the slide to the right
will increase the quantity. However I have noticed several users comment
that the two ends seemed reversed. They wanted it to read 
"increase and decrease, not decrease and increase" especially in 
the instructions. 
In speach and text people usually put the positive 
or greater value first, (increase and decrease, positive and
negative, more or less, on or off, etc.) . So there is a contradition
between expectation when reading and performing; users want it two
ways.
This proved problematic only for users who took instructions literally.
They read tht the control increased or decreased some value and then
were confused when the slide was labelled in the reverse order.