Deming (following Shewhart) 等人的概率哲學 (David Kerridge 教授)

我兩月前希望英國的David Kerridge 教授能談一下概率的哲學
他昨天寫個簡要的說明


Dear Hanching

I am sorry to have been such a very long time in answering your
interesting question. There have been two reasons. I have been ill, and
found it hard to concentrate. But that would not have stopped me if the
question did not require a lot of concentration.

Both Dr Deming and Sir Harold Jeffreys held views of probability that
are different from those usually taught. They are, in fact extreme
cases. Sir Harold Jeffreys held views that are regarded by most people
as very out-of-date, being the same as those held by LaPlace a hundred
years before.

Deming (following Shewhart) based his views on the new philosophy of
science that came in with Relativity and Quantum Theory. This is so
advanced that few other statisticians are even aware of it yet. Shewhart
assuned that it would be universally adopted in time: but there is
little sign of it yet. (John W Tukey is the one exception that comes to
mind)

That's *why* there is a difference, and why both differ from the views
of probability in most textbooks. But to explain what the difference is,
is not easy, without explaining the different philosophical viewpoints.

That's what I have spent a lot of time trying to do. It makes it no
easier that Deming did not explain his view of probability explicitly. I
had to deduce it from remarks he made in research meetings, and in
papers like "On Probability as a Basis for Action."

Note that for Jeffreys, and those before him, probability is simply a
matter of logic: action may result from probability, but the nature of
probability is not defined in terms of action. For Shewhart and Deming,
everything scientific is defined in terms of action, rather than
thought, because actions can be observed, while thoughts can not.


This really requires a book to explain it - a pity Shewhart didn't write
one on this topic. But he probably felt that the problem of defining
probability was still not completely solved.

I spent years on this problem using the same advanced philosophical
viewpoint as Shewhart, long before I met Deming. I couldn't find any
other statistician in the UK who understood what I was saying. And I
heard Deming discussing his ideas with others, who couldn't see what he
meant. So he had the same problem.


This may be enough to be going on with. The rest may take a long time to
express in simple words. I intend to try, but it can't be hurried.



Best wishes

David