Tag Archives: preisendorfer

Preisendorfer on Centering "Conventions"

In our GRL article, we pointed out that MBH98 had misrepresented their principal components methodology as being "conventional", when it wasn’t. At realclimate , they argued that it was an alternative centering "convention".

Errors Matter #3: Preisendorfer’s Rule N

In the last two days, I’ve argued that it’s insufficient for Mann et al. to merely “get” a hockey stick shape some other way, but that they have to show that any such salvage reconstruction meets the representations and warranties of MBH98 as to reasonably even spatial sampling, robustness, statistical skill and proxy validity. I’ve […]

Was Preisendorfer’s Rule N Used in MBH98 Tree Ring Networks?

Mann et al. have recently argued that they can salvage MBH98-type results, even with correct PC calculations by also using “the standard selection rule (Preisendorfer’s Rule N) used by MBH98”. They say that this method permits them to retain 5 PCs in the North American network. The reason why this matters to them is that […]


[Climate Audit was started on Jan 31, 2005. Prior to its startup I had some notes at a prior website http://www.climate2003.com, which John A transferred to the CA blog at its start-up.] If 2 PCs are used in the AD1400 North American network along with conventional (centered) PC calculations, we argued in our Nature submissions […]