[comp.cog-eng] The use of Red and Green

jwk@lanl.gov (John W. Keller) (02/27/90)

I am developing a computer based instructional system that uses
the colors green and red for, what would seem to be, the obvious
feedback for correct and incorrect answers. This is coupled with
an audio feedback and the score is kept with a series of green and
red squares. 

It was brought to my attention that since the most common color
blindness is red/green that it would be difficult for some people
to use the visual score.

I would like to find out if there has been any research or if there
is a prefered set of colors to use in this type of situation.


Thanks in advance. 

John Keller

******************************************************************
John Keller			Staff Reasearch Assistant
LANL, MS M997			Los Alamos National Laboratory
PO Box 1663
Los Alamos, NM 87544		jwk@beta.lanl.gov
******************************************************************
As usual, my opinions are my own.
***********************************

wjh+@andrew.cmu.edu (Fred Hansen) (02/27/90)

Excerpts from netnews.comp.cog-eng: 26-Feb-90 The use of Red and Green
John W. Keller@lanl.gov (941)

> It was brought to my attention that since the most common color
> blindness is red/green that it would be difficult for some people
> to use the visual score.


Why not display the responses with icons as well as colors.   Maybe an X
for wrong and a check for OK.

Fred Hansen

maner@bgsuvax.UUCP (Walter Maner) (02/27/90)

From article <44532@lanl.gov>, by jwk@lanl.gov (John W. Keller):
> I am developing a computer based instructional system that uses
> the colors green and red for, what would seem to be, the obvious
> ... 
> It was brought to my attention that since the most common color
> blindness is red/green that it would be difficult for some people
> to use the visual score.
> 
I applaud your sensitivity.
The obvious solution is to allow full user customization of colors.
In addition, there should be multi-sensory redundancy such that no
important information is presented in only one modality.

WALT

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ianf@nada.kth.se (Ian Feldman) (02/28/90)

In article <5468@bgsuvax.UUCP> maner@bgsuvax.UUCP (Walter Maner) writes:
>From article <44532@lanl.gov>, by jwk@lanl.gov (John W. Keller):
>> I am developing a computer based instructional system that uses
>> the colors green and red for, what would seem to be, the obvious
>> ... 
>> It was brought to my attention that since the most common color
>> blindness is red/green that it would be difficult for some people
>> to use the visual score.
>> 
> I applaud your sensitivity.
> The obvious solution is to allow full user customization of colors.
> In addition, there should be multi-sensory redundancy such that no
> important information is presented in only one modality.

  Actually, full user customization, especially of permanent- or
  default-changing type, is definitely not the answer.  User A dis-
  covers the customization feature and replaces the defaults with what
  she finds "nice" and "pleasing" colors.  User B is then called upon to
  use the same computer/ the same copy of the program but never gets
  around to read the manuals, and even if she did, wouldn't know how
  to proceed anyway.  Thus she is forced to use someone else's defaults,
  rather than the primary well- or better-balanced ones.

  If you absolutely have to signal back to a user via colors than make
  it a combination of color-and-pattern (or shape).  Then you can keep
  one of the elements constant (non-changeable) and allow customization
  -- within reasonable borders and definitely of non-default-
  replaceable type) of the other.

  BTW: Julian Tuwim, one of the best modern Polish poets wrote once of
  tramway cars in 1930's Lodz in Poland, that were called (and marked)
  as "red 2", "green-with-stripes 11" and so on [am not sure about the 
  exact combinations though]. I was subsequently told, that the reason for
  that was the fact that there were plenty of illiterates among the
  lower-class workers there.  Makes one wonder how such bi-type marking
  principle was arrived at, however.

--Ian Feldman /  ianf@nada.kth.se || uunet!nada.kth.se!ianf
             / "Go ahead, make my day, tell me to RTFM"

pjc@r1.uucp (Peter Crowther (CAG ra)) (02/28/90)

In article <3037@draken.nada.kth.se> ianf@nada.kth.se (Ian Feldman) writes:
>In article <5468@bgsuvax.UUCP> maner@bgsuvax.UUCP (Walter Maner) writes:
>>From article <44532@lanl.gov>, by jwk@lanl.gov (John W. Keller):
>>> I am developing a computer based instructional system that uses
>>> the colors green and red for, what would seem to be, the obvious
>>> ... 
>>> It was brought to my attention that since the most common color
>>> blindness is red/green that it would be difficult for some people
>>> to use the visual score.
>>> 
>> I applaud your sensitivity.
>> The obvious solution is to allow full user customization of colors.
>
>  Actually, full user customization, especially of permanent- or
>  default-changing type, is definitely not the answer.  User A dis-
>  covers the customization feature and replaces the defaults with what
>  she finds "nice" and "pleasing" colors.  User B is then called upon to
>  use the same computer/ the same copy of the program but never gets
>  around to read the manuals, and even if she did, wouldn't know how
>  to proceed anyway.  Thus she is forced to use someone else's defaults,
>  rather than the primary well- or better-balanced ones.

**** MILD CHILI-LEVEL FLAME ON ****

Oh, come on! Do you SERIOUSLY mean to say that the defaults are the same
for EACH USER? Give 'em all a local work space and let them do what the
hell they want within it. Multi-user but single-username systems are
THE most irritating systems to work with.

It should cost about 1 day's programming, plus the user entering
a unique username (let 'em use christian+surname, plus initials to
disambiguate. No silly system-allocated names to remember then. Oh yes,
no password - unless there's really confidential info in there). I
consider the results to be well worth that expenditure.

**** FLAME OFF ****

		- Peter

Peter Crowther, Dept. of Electrical Engineering, University of Manchester,
		Manchester M13 9PL, England.
Internet: pcrowther@r1.cs.man.ac.uk	Janet: pcrowther@uk.ac.man.cs.r1
USENET:   mcvax!ukc!man.cs!pcrowther	Fishing net: Device for catching fish

mmt@dciem.dciem.dnd.ca (Martin Taylor) (03/02/90)

Peter Crowther mildly flames the idea that there might be a problem in
allowing per-user user-controlled default colours for signifying correct
and wrong answers.  The original poster had noted that the conventional
red and green were confusable by colour-blind people.

It is NOT a good idea to let users choose their own colour codes.  They
almost always do it wrong (and there is no value judgment in that word).
Even paid consultants often do it wrong.  So when colour coding is to
be used, the colours should be chosen with some insight into the capabilities
of the visual system, and of conventional coding patterns.  In respect of
the colour-blind failure to discriminate red and green, there are two
main types of red-green blindness, distinguished by having different lines
of colour confusion in the CIE diagram.  Look them up in a handbook, and
choose colours that lie athwart both sets of confusion lines (from distant
memory, I think a yellowish green and a mauvish red should be OK, and
should be distinguishable also by the rarer blue-yellow blind people).

I once visited an Admiralty research laboratory, and was shown a fairly
complex display.  I asked why they had used certain colours, and suggested
some changes, which were made on the spot.  A few months later, I got a
message saying that my half-hour visit had done them more good than the
substantial contract that had led to their original colour codings.  To
code colours, I emphasize, you have to know what you are doing.  Don't
let the users select whatever pretty set they want, because as like as
not, they won't be able to do the work they are supposed to do.
-- 
Martin Taylor (mmt@zorac.dciem.dnd.ca ...!uunet!dciem!mmt) (416) 635-2048
"Viola, the man in the room
doesn't UNDERSTAND Chinese. Q.E.D."  (R. Kohout)

david@uhccux.uhcc.hawaii.edu (David Lassner) (03/05/90)

Another possible argument against asking the user to
customize colors may be the context of this particular
application.  Remember that he was describing a CBT
situation, in which the user may not be looking at the
software as a tool that s/he fools around with to
personalize for long term use.  Rather it may be some
required interaction that the user isn't particularly
thrilled about or just a short-term means to an end.
Diverting the user from the training/learning objective may
be non-optimal in this case.
-- 
David Lassner, University of Hawaii Office of Information Technology
Internet: david@uhccux.uhcc.hawaii.edu		Bitnet: david@uhccux
Voice: 808/948-5023				Fax: 808/948-5025