Fil,

Being initially trained as a computer and cognitive scientist, during the late 80's, logic, computability, numerical analysis, game theory and other utterly fascinating things run in my veins.
The issues you raise are important. Without going into details, there are more complex logic frameworks that could be used; such as probability logic, Bayesian logic, modal logic, etc. I would also refer to the so called "frame problem" in order to work with the complexity that these kinds of analyses bring. Enough of logic.

But, let's look at this from a "risk" and "design" point of view. There are three different occurrences that we are working with; the earthquake, the tsunami and a nuclear accident. And they are related in a chain of consequences.
Based on what we know, earthquakes and tsunamis occur more often than nuclear accidents. Even major earthquakes and tsunamis occur more often than nuclear accidents. We know that more people have died in earthquakes than in nuclear accidents (measured over the 50+ years of nuclear power plants). We also know that human decision making directs the probabilities of nuclear accidents, that human decision making under a crisis situation is problematic, and that human decision making does not influence the probability of earthquakes or tsunamis.
So, _if_ (note: not _when_) we want to build safe systems in a society, which of the probabilities should direct our (design, planning, engineering) decisions, and what would be the consequences of one or the other?
(It's an open question, not meant to assume that one or the other is better or more effective; that would in an ideal society be the role of political decision making.)

What is fascinating is that we end up in the area of "resilience engineering", and as Mattias Arvola pointed out in an earlier email, the role of design in resilience engineering (and vice versa) is not that well understood. Jonas Lundberg at Linköping university have started to work with these issues.

/Stefan

-----Original Message-----
From: PhD-Design - This list is for discussion of PhD studies and related research in Design [mailto:[log in to unmask]] On Behalf Of Filippo A. Salustri
Sent: Thursday, March 17, 2011 12:45 PM
To: [log in to unmask]
Subject: Re: Why the design profession wouldn't have avoided the Japanese nuclear crisis

Stefan,

I'm an engineer.  I know about the power of statistics and uncertainty.  And
my doctorate was on the use of logic in design.

There's two immediately evident issues here:

* Just how robust are the actual calculations of the probabilities?  As far
as I know, the probability of death by nuclear accident based on extant
examples is pretty much zero.

* There are many other forces (economic, political, etc) at work in a real
situation that your logic would have to accommodate to help one arrive at a
sound conclusion.  No one does that kind of logic.  I'm not even sure it
would be tractable with known methods for a case as complex as Fukushima.

The problem with basic logic is that it's basic.  It doesn't handle the
complexity of the situation.

Cheers.
Fil


On 17 March 2011 07:15, Stefan Holmlid <[log in to unmask]> wrote:

> Well. Time for some maths; or at least basic logic.
>
> 1) If a nuclear accident is more unlikely than the events we've just
> witnessed, the precautions taken should be based on the likelihood of these
> events and their effects
> (notice that we are not talking about _possible_ effects; when the water
> floods land physics (fluid mechanics) will tell us where it will flow).
>
> 2) If a nuclear accident is a little less unlikely than the events we've
> just witnessed, what would logic tell us would be the rational decisions to
> make about precautions?
>
> 3) If a nuclear accident is much more likely than the events we've just
> witnessed, what would logic tell is would be the rational decisions to make
> about precautions?
>
> NOTE: we also know the effects of nuclear accidents.
>
>
> /Stefan
>
> --------------
> Stefan Holmlid, associate prof Interaction & Service Design
> E: [log in to unmask] | P: +46 13 285633
> W: http://www.ida.liu.se/~ixs/ | T: @shlmld
> A: IDA, Linköping University, 581 83 LINKÖPING
>
>
-- 
Filippo A. Salustri, Ph.D., P.Eng.
Mechanical and Industrial Engineering
Ryerson University
350 Victoria St, Toronto, ON
M5B 2K3, Canada
Tel: 416/979-5000 ext 7749
Fax: 416/979-5265
Email: [log in to unmask]
http://deseng.ryerson.ca/~fil/