A new and interesting paper by Carl Wunsch is online here (thanks again to Eduardo Zorita for the reference and link). The abstract says:
The human eye and brain are powerful pattern detection instruments. Coupled with the clear human need to perceive the world as deterministic and understandable, and the often counter-intuitive results of probability theory, it is easy to go astray in making inferences. In particular, many examples exist where attention was called to apparent extreme behavior, whether in time or space series, or in the appearance of unusual patterns, that are just happenstance.
Wunsch quotes the following “verse” as his text:
My eye is better than any statistical test.
Well-known paleoceanographer, circa 2001.
To which, any person attending the NAS Panel presentations in 2006 cannot help but add:
“I am not a statistician”
Michael Mann to NAS Panel, March 2006
There’s an interesting tie-in in one of the citations in this article to AR4. Wunsch quotes an example from Wunsch (1999). which includes a demolition of the statistics in Trenberth and Hurrell, 1997. Ironically, in response to criticism of the significance testing for trends in chapter 3 of AR4 from Ross McKitrick, IPCC reviewers (also proving that they are not statisticians) invoked an unprecedented use of the Durbin-Watson test – a usage unknown in statistical literature off the Island ( the Durbin-Watson test is fine, it’s just the IPCC usage was nonsensical – see posts last summer on this topic.) As purported justification for this, they cited the Trenberth and Hurrell reply to Wunsch (1999), which Wunsch’s response rebutted.
Ross McKitrick’s criticism was as follows:
3-1132 A 116:55 116:56 The sentence beginning, “Nevertheless, the results depend ” is vague, disputatious and incorrect. It applies more to the REML results, which are presented without such caveat in the chapter. No citation to any literature is given to defend the implication that fractionally-integrated estimators are less physically-realistic than the linear regression models used elsewhere. Persistency models were developed in hydrology precisely to improve physical realism, so as to provide a better match between the stochastic model and the geophysical phenomena. As for transparency, the lack of transparency of GCM’s or other numerical models is never regarded as a deficiency in IPCC documents. And there is no sense in which fractional-integration models lack transparency–the methods are well-known and code is published. They are not trivial, but that doesn’t mean they are not transparent. The sentence is wrong, unnecesary and should be removed. [Ross McKitrick (Reviewers comment ID #: 174-13)]
To which the IPCC reviewers replied:
Fractionally-integrated estimators have not been shown to be good models or fits to the data. On the contrary some examples exist where it is demonstrated they are not (e.g. Trenberth, K. E., and J. W. Hurrell, 1999: Comment on [Wunsch 1999]: The interpretation of short climate records with comments on the North Atlantic and Southern Oscillations. Bull. Amer. Met. Soc., 80, 27212722.
The Trenberth and Hurrell comment was not an exposition of statistics by renowned statisticians, but an exchange sparked by Carl Wunsch’s 1999 criticism, covering somewhat similar ground as the present article. Although AMS publications are mostly online, Trenberth and Hurrelll 1999 is not online (though it is in the paper copies of the journal.)
So when Wunsch (2007) rebuts Trenberth and Hurrell one more time, it is in a debate that has seemingly been going on for a decade without acceptance of Wunsch’s points by rank-and-file IPCC climate scientists who are not statisticians.