"There is no such thing as a fact" - Not So

[Paul Hollingworth <PH@paulholl.demon.co.uk>]

Some way back up this thread Dirk van Putten introduced an alleged
quotation of Dr Deming's : "There is no such thing as a fact"

Kromkowski@aol.com then writes
>1. No such thing as "fact" (although Deming I think wrote "true value" not 
>"facts") and "the most important figures": these can easily become slogans 
>and used for purpose of defending the "status quo", which I think is a misuse 
>of what Deming was getting at.

I agree with JDK.
I'd like to shed a little light on this if I can. Not because I am
concerned that people don't go around 'misquoting our leader'. Not at
all.  But Dirk, (quite inadvertently I'm sure) does seem to have caused
some confusion, and that can only be helpful if we use it as an
opportunity to learn.

I have no recollection of ever hearing Dr D say "There is no such thing
as a fact" and I don't recall reading it either. That's not to say he
never said it, obviously, but I know he did state quite the reverse:
Some information is factual. 

My telephone number, for example, is a fact. But my telephone number is
not the result of something being measured or counted. As soon as we
count or measure something, there are no facts, because there are no
absolute values. I think this must be where this mis-quotation has
sprung from because Deming certainly said "There is no true value of any
characteristic or condition that is defined in terms of measurement or
observation" (for the avoidance of doubt I am quoting from page 107 of
TNE, not from memory).

His best example of this IMHO was the speed of light - which is of
course a universal constant. But the speed figure you get depends on how
you measure it. Hence the need for operational definitions.

Even though it can be a fun experience, I have seen some people get very
frustrated by this when they learn that they can never measure something
'perfectly'. For others its a liberating experience (now doomed to a
life-time of 'its near enough' DIY projects). But I think Dr D would
have simply called the absence of absolutes a 'fact of life'.

So why is this concept so very important? 

A final quote* from Dr D the statistician:
"Statistics are a basis for action, and the more we know about the
limitations of a figure, or of a procedure, the more useful it becomes".

Regards
Paul H


* Sample Design in Business Research pub Wiley 1960

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Paul Hollingworth                       4GM Consulting  
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