Jan Merks is an expert in sampling theory and works as an independent consultant out of Vancouver, Canada. He has a web site which I don't have to hand, where all of these opinions are repeated and amplified.
Jan first starting publishing anti-geostatistics articles in 1991 or 1992 and the article "Geostatistics or Voodoo Statistics" appeared in every mining publication from the Engineering and Mining Journal to the Northern Miner newspaper. He republishes every so often and had one a few years ago in the Mining Journal on April 1st. The articles start with a quotation from Tolstoy to the effect that even the most intelligent of people can turn a blind eye to facts that don't fit their own world view. It is ironic that he does not realise this quotation is apropriate to his own world view too. His basic premise is that geostatistics is a con job foisted on an unsuspecting industry by consultants trying to rip them off for large sums of money. He supports this view by pointing out that the semi-variogram is divided by the number of pairs of samples (N) and not by N-1 when every statistician knows that variances are divided by N-1 not N. The point missed here is that variances are divided by N-1 because we estimate the population mean. Semi-variograms are not divided by N-1 because we assume the population mean (difference) to be zeto and do not estimate it. His second point is that kriging with (say) k samples should have k-1 degrees of freedom. This is not true becuase the variance/covariance or semi-variogram terms used in the kriging system are based on the total number of pairs used in the construction of the graph. I once asked Noel Cressie about this and he said that the degrees of freedom in the kriging system would be n(n-1) where n is the total number of samples in the data set. Back in 1992, I invited Dr Merks to come down to a course I was giving in Reno to put his point of view and debate it with myself and the students and staff at University of Nevada-Reno. I still have his letter on file. It basically says, I don't see the point you aren't going to listen anyway. Before you ask, the only reason I did this was because his articles referred to only two geostatistical publications: Michel David's Mining Geostatistics and my Practical Geostatistics (1979). He also couldn't spell my name right and I wanted to give him the opportunity to change that. It was several years before an editor pointed out to him that there is no 'e' on the end of "Isobel Clark". Isobel http://uk.geocities.com/drisobelclark/practica.htm
* By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to [EMAIL PROTECTED] Signoff ai-geostats