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From: wtangel@cais.cais.com (Bill Angel)
Subject: Re: Ariane 5 - not an exception?
Date: 1996/07/27
Message-ID: <4tdipd$8o0@news2.cais.com>#1/1
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references: <Dv45EJ.8r@fsa.bris.ac.uk>
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newsgroups: comp.software-eng,comp.lang.ada
Date: 1996-07-27T00:00:00+00:00
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In article <Dv45EJ.8r@fsa.bris.ac.uk>,
Simon Bluck <simonb@pact.srf.ac.uk> wrote:
>
>I.e. each data item would have a truth value of 1.0 for good data,
>0.0 for absolutely rotten data, utilising values in between if you
>have some idea how good the data is...Taking a probabilistic 
>attitude to data would bring a lot of software into the real world where
>failures can happen at all levels...

I believe that your idea is a very valid one.

It is so valid, that someone else has already thought of it!

You should check out the topic of "fuzzy logic" as it is applied to
industrial control. As you are suggesting, "fuzzy logic" allows one to
determine the membership of some measurement in the set comprised of "good
data". "Fuzzy logic" can also formulate a response when the input data
from various measurements yield conflicting directives as to how the
system should behave. If necessary, the response (to conflicting, out of
range, or inconsistent measurements) could be specified as a set of
directives with different precedence levels.  The directives could be
"heuristic" in nature and could have been  specified by human experts
during the analysis/design stage of the project. 

 -- Bill Angel