RE: imprecision versus uncertainty and vagueness

Rod Davison (rdavison@sprint.ca)
Fri, 3 Sep 1999 09:53:05 +0200 (MET DST)

Although I am not aware of the formal definitions of these terms, being a dabbler myself; the semantic difference I think goes something like this:

1. Imprecision: The coarseness of measurement. Thus to say that I have about $100 in my bank account is more imprecise than to say I have $96.13 in my bank account. Note that this is not the same as accuracy since I might be very precise by saying I have $96.13 in my bank account when in fact I have $3.45.
2. Uncertainty: The inability to be certain about one alternative over another another, usually because of a lack of information. Thus I may have $100 or $50 in my account depending on whether or not my wife has cashed the $50 cheque I gave her. Until I look, both outcomes are possible and I cannot select with certainty among them. A commonly cited variation is found in the spirit of the uncertainty principle which states which implies that when two quantities ore related (like velocity and position) one cannot be certain about both at the same time.
3. Vagueness: This refers to the fact that there may not be clear boundaries between alternatives and that we can have mixed states (the core idea of fuzziness). At what temperature does warm become hot?

It is possible to have all three co-occurring. That pan of water is about 10 degrees (imprecision), or it could be about 40 degrees (but I can't tell just by looking - uncertainty), more or less, which might either be coolish or cold or warmish or tepid, depending on how you want to look at it (vagueness).
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Rod Davison
Davison Instructional Services Ltd
900-275 Slater Street, Ottawa ON, K1P 5H9, Canada
Voice: (613) 569-7624 Fax: (613) 834-8273 Email: rdavison@sprint.ca

-----Original Message-----
From: Peter Rijnbeek [SMTP:rijnbeek@mi.fgg.eur.nl]
Sent: Thursday, September 02, 1999 9:17 AM
To: Multiple recipients of list
Subject: imprecision versus uncertainty and vagueness

Can anyone explain to me the difference between imprecision, uncertainty,
and vagueness, because this is very confusing to me.

If you have any references about this subject please respond also.

With regards,

P.R Rijnbeek, MSc.
Medical informatics
Erasmus University Rotterdam
The Netherlands.

rijnbeek@mi.fgg.eur.nl

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