And how many of your viewers understood the “changing 2 variables at once” issue that is hidden inside of the language “use the covariance matrix”, before I belabored it? Also, there are arguments for either correlation or covariance matrix, so you should discuss each. When pinned down, you do not get behind the covariance matrix! So certainly describing the covariance matrix as “conventional” is a bit of snuck in spin.

I suspect that he’s a grad student at Scripps or some other Temple of AGW who feels he can get back at those who have exposed his high priests by being a nuisance.

No he’s not. I know for whom he works so I can assure you he’s not a grad student at Scripps.

But even if he was, his output suggests someone who is trying to get to grips with the complexities, and not someone wasting Steve or Ross’ time just for the sake of it.

That said, TCO doesn’t demonstrate a very good understanding of PCA or its application in MBH. Some of his questions are difficult to answer because they don’t make sense in the first place. I think Ross was having problems with this in some of his “unresponsive” replies.

Sometimes I can be a bee-yatch, too.

On the content: yeah, I saw where Steve called it “impossible to say”, but I was still concerned that it was a bit of a rowback from earlier firm assertion (I think he edited an earlier post after comments had gone on) and I wondered if the “hard to say what it is” is a bit of equivocation to make it look like less of a correction. If a more accurate statement would be “they did do a ‘funkky, flawed’ geo-weighting. If its completely unclear what the are doing or if a reasonable interpretation is that the “grouping” is geo-weighting, but of a poor sort.

There’s more to my question than just this post, because in another post, Steve printed colored graphs of the various groupings (the one where Dave D. gave me a bravo zulu). I’m wondering if those groups are the same “hard to understand weightings” which Steve mentions here). Because I think we would agree with calling those geo-groupings and (if compining them is different than combining the subordinate series without grouping) that this is geo-weighting. Essentially it looked in that post like taking a subaverage of geographic areas.

Which part of “it’s impossible to say” don’t you understand ? Is it the apostrophe in the “it’s” that’s throwing you, as “impossible to say” seems quite clear to me ? There is some weighting system applied, but it doesn’t appear to correlate to anything obvious would seem like a reasonable translation to me.

Ease up buddy, I think you add some value trying to extract an ordered array of charges against MBH, but some clarity in your own thought processes would surely make that a less laboured process.

Apologies in advance, Steve, if you think me putting my oar in is unnecessary.

Just saw this:

Update – let me clarify a little. In the MBH regression stage (but not the tree ring PC stage), there are weights but it’s imposible to say that they are geographic weights. I don’t know what they are. A&W do calculations without any weights. There are some very odd QC issues. For example, there are 4 different series from Quelccaya ice cores used. Instead of averaging two different O18 series, they are used individually; same with two accumulation series. These are all in the small MBH99 network. The Gaspe series is used twice – once in the North American tree ring network, once individually. Series from Spruce Canyon CO are used 7-8 times – the EW and LW series are used in the Stahle/SWM network; then a near duplicate versions are sued (the first 100-125 values are identical); then the RW and MXD series are used in the NOAMER network; then the MXD is used in the Briffa composite and I think that the RW is used in the Fritts composite. In my grandmother’s trunk, there is a…

I think you edited it back into a post after I had replied already. I really advise against doing this. It is better to correct yourself with a post lower down. If you feel so, so scared of being misquoted by the evil guys, then put a bold comment in that there is an update below. but editing in stuff after the fact (or even the damn voiceofGod RealClimate style responses to other people) are poor for the discussion (don’t see a new post) and they seem heavy handed. If you want to close a thread or ban a user, fine. But don’t play unfair within the discussion.

Ok…on the content. Are you saying then that there WAS a geographic weighting of some sort? (and then seguing to what a miserable form of geoweighting they were)? And what about the “groups”. Do the groups provide “geo-weighting” or were they just used for regional effect mapping?

P.s. I would be nice to see a list of the errors in MBH. Organized into categories and a heirarchy in a MECE/Minto manner.
P.s.s. “interactions” can be listed too, but obviously they are a second order effect. I mean when I analyze a business and start with Revenue=price*volume. looking at each factor allows me to think about what the cause of a revenue change was. Of course, Ross can remind us that “elasticity” does exist. So the two variables are not independant. But we can still do a heirarchical trouble-shooting analysis. with the interaction as a second order issue to examine. (And it may not be relevant). In the example above, if I’m a minor producer in a free competition market, my change in volume has minimal effect on price.