Comments on: Graybill and Idso [1993] Online

By: tom

tom — Wed, 10 Mar 2010 10:08:12 +0000

Does anyone have a valid link to the graybill and idso paper? The old one is now dead.

By: Scott

Scott — Fri, 24 Aug 2007 00:09:15 +0000

Scratch that – I did some exploring and found it here:

http://data.climateaudit.org/pdf/others/graybill.idso.1993.pdf

By: Scott

Scott — Thu, 23 Aug 2007 22:55:06 +0000

Steve,

The link to the Graybill and Idso [1993] online pdf is no longer valid. If it has moved, can you post the new link?

By: David Stockwell

David Stockwell — Thu, 21 Sep 2006 19:28:43 +0000

Well, I think your argument is that perhaps all tree rings don’t correlate well with temperature or have some other problem would be cause for concern too. But that doesn’t mean BCPs shouldn’t be picked on does it? If you throw out BCPs, highlight divergence, the authority of treerings to climate change fades, and dendro people go back to what they were doing before, perhaps including the type basic analysis you suggest.

By: TCO

TCO — Thu, 21 Sep 2006 19:14:45 +0000

Let’s say that I have a thesis that the high cost of the war in Iraq is related to Haliburton’s KBR business unit. Those bcp-loving, Cheney-led privateers! I go do some analysis and find out that KBR has increased its percentage of the work (among contractors) from 5% to 50%, I find that in the general market, they are only 10% of the overall, but in Iraq work, that they are…50%. In addition, I find a long litany of overcharges that they’ve had on projects. Sounds like KBR (Haliburton) is the problem, no? No.

Now I go and examine KBR in comparison to other contractors in Iraq, to the general market for contractors. And I find that they’re all about just as bad. Thus I find that the issue of KBR’s specific issues, of their “loading” was a distraction. The fundamental issue is something about government contracting overall.

This seems like a simple and relevant concept to check on, no? Just like knowing how mining affects the hockey stick itself, rather then an intermediate is a relevant issue also, no? Why is there so much resistance to considering things fairly on a site that is supposed to be about fair analysis?

By: David Stockwell

David Stockwell — Thu, 21 Sep 2006 18:59:28 +0000

Awww. Its silly. Its like, OK Mann made chocolate cake. If I vary all the ingredients I get a range of other stuff, only some of which is chocolate cake. So… maybe Mann could have made something else. The response is — analytical decisions are not neutral. And then you get into endless complex arguments about the best way to make chocolate cake. Waste of time IMHO.

By: TCO

TCO — Thu, 21 Sep 2006 18:50:21 +0000

I lubbed it before you. I wanted to make babies with it.

By: bender

bender — Thu, 21 Sep 2006 18:10:29 +0000

Re #39

Look at BC05 and how he does a full factorial.

Ah, so you like BC05 now? Very good. Well-written paper, too. [Sorry, couldn't resist ]

By: TCO

TCO — Thu, 21 Sep 2006 18:06:40 +0000

You use the term robust in it’s proper meaning, but seem to devolve to the “connotation” level when remarking on non-robustness. My point is how bad is it to be non-robust? As you referenced, this is a complicated issue (when to take data out of a set, when it is relevant to expect performance with data out of the set). My point is that since it is non-trivial, the onus is on you to extend your argument more if you want to say that the non-robustness is bad, rather then just to note the point itself.

Biondi/NAS is crap in terms of explication of bcp proxy effectiveness. You are playing BS debate games, not doing science (or even good business analysis) in citing an expert rather then an argument. And in this case, since you know the expert hasn’t looked at the problem in detail and even (NAS panel) has a history of making unsupported, wrong, unexamined statements, your comment is tendentious.

Steve, you, definetely you, are the one who is having a problem with issue analysis. If there is a problem with an interaction of data and methods, fine. But you have not clearly defined if your critique has multiple legs of a stool supporting it (independant errors in MBH) or if it requires everything to “hang together” to buttress your critique. It is trivial to consider method change, data change and (method and data change) as variables to consider in terms of effect on the reconstruction. Look at BC05 and how he does a full factorial. And when we go to examine a specific issue, you wiggle and want to draw in other issues. If I directly ask a question on the effect of X28 (in isolation), then that is the question which I’m asking. Responding by trying to shift the discussion to X31 or to the interaction of X28 and X31 is non-responsive and evasive.

By: David Stockwell

David Stockwell — Thu, 21 Sep 2006 18:04:07 +0000

I would think to any reasonable person the fact that removal of a couple of data point changes the story is enough to throw out all studies that rely on them for their conclusion. It doesn’t matter if they are 5000 years old or like CO2 or whatever, a cautious person would be very concerned with studies suggesting world policy should be based on just a couple of trees. Having the NAS backing is nice, but a sad reflection that its necessary.