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What are the
Chances? Bart K. Holland
If you have ever wondered about the
chances of a Prussian cavalryman being kicked to death by his
horse or if you prefer to work out your own life expectancy by
staring at life tables, then Bart Holland’s excellent primer
in probability is a great place to start. He even explains
Henri Poincaré’s technique for finding out if your baker is
diddling you.
An unexpected strength of the book
is Holland’s discussion about testing hypotheses, which
illustrates how probability is an inherent part of so much
scientific analysis. For example, in the Second World War,
Londoners frequently asserted that Germany was targeting its
V2 bombs because they fell in clusters, but there was no known
technology that could achieve such accuracy.
To test the targeting theory,
London was divided into 576 squares. While 440 squares
suffered no hits or one hit, 35 squares received 3 hits and 8
squares received 4 or more hits. Intuitively, this feels like
targeting, but in fact the data is a very good fit to a
Poisson distribution, implying that the bombs fell randomly.
Of course, the same approach can be used to determine whether
the clustering of disease or anything else is significant or
coincidence.
In a time when anecdote and panic
seem to influence public policy more than objective analysis,
Holland has provided a welcome reminder of the power of the
analytical approach. Stephen Jay Gould once wrote that a
misunderstanding of probability may be the greatest of all
impediments to scientific literacy. The problem is that the
people who read this book are probably those who already to
some extent appreciate the scientific method.
Find out more at
Amazon.co.uk or
Amazon.com |