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Spatial
dependence
After
my geostatistical peers at CIM Bulletin unanimously rejected
Precision estimates for ore reserves, I submitted
the paper to the Journal of Mathematical Geology. One
of JMG's reviewers suggested publication and the other
rejection. Professor Dr Robert Ehrlich, JMG's Editor,
agreed to have Dr Margaret Armstrong, his Associate Editor,
review the paper once more but to no avail. JMG's Editor,
after some argument and debate, sought advice from Dr
Andre Journel, Professor at Stanford University, coauthor
of Mining Geostatistics, and a prominent authority
on the art and science of kriging. Here are the highlights
of Journel's thought-provoking musings:
"Merks'
anger arises fro [sic] a misreading of geostatistical
theory, and of a reading too encumbered by classical
"Fischerian" [sic] statistics".
".spatially
distributed data should be considered a priori
as dependent one to another, unless proven otherwise
(my emphases in bold!)".
"The
reason for the denominator (n-1) in the classical
expression of the variance estimator is indeed correction
of the bias introduced by the prior estimation of the
population mean by the same n data zi. However, that
correction is valid if and only if the n
data zi can be considered independent one from
another. In a spatial context with spatial dependence,
the case is a bit more complex requiring some more detailed
notations".
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