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From: Nancy Leveson <leveson.nancy8_at_xxxxxx>
Date: Thu, 19 Nov 2009 05:13:40 -0500
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  >What is most important for safety cases is not "how people actually
  >argue", but whether the arguments given in them for the conclusions,
  >that the system is adequately safe, are correct.

Exactly, but this is not a formal logic problem, it is an engineering
problem.
I can make a perfectly logical argument that is completely wrong from an
engineering standpoint.

This whole discussion is puzzling me. I don't find in practice that the
arguments
of engineers justifying the safety of their designs are illogical in most
cases,
but that they are incorrect from an engineering standpoint (e.g., assume
some probability that is not correct).

As someone else tried to point out, the problem is designing and building a
system that is safe, not arguing after the fact that it is safe. If
safety-driven
design is used, then the argument at the end is simple (and the least
important
part of the process if one has to prioritize them).

Nancy

On Thu, Nov 19, 2009 at 1:08 AM, Prof. Dr. Peter Bernard Ladkin <
ladkin@xxxxxx> wrote:

> "
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> Subject: Re: [sc] Aristotle and Russell
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> On Nov 19, 2009, at 2:52 AM, Mauricio Peixoto wrote:
> >
> > It seems to me there is a gulf between those concerned with how
> > people, dumb as
> >
> > they are, actually argue, and those concerned with "correct"
> > argumentation. A new
> >
> > perspective is needed that does some justice at least to both of
> > these points.
>
>
> If you look at the Walton paper I cited, you will find that there is a
> fairly sizeable
> academic industry concerned with "how people actually argue". I don't
> find his
> paper particularly enlightening, but maybe some will.
>
> What is most important for safety cases is not "how people actually
> argue", but whether
> the arguments given in them for the conclusions, that the system is
> adequately safe, are
> correct.
>
> PBL
>
> Peter Bernard Ladkin, Professor for Computer Networks and Distributed
> Systems,
> University of Bielefeld, 33594 Bielefeld, Germany
> www.rvs.uni-bielefeld.de +49 521 880 73 19
>
>
>
>
>
>
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Received on Thu 19 Nov 2009 - 10:13:47 GMT