Sometimes people deny something that seems so obvious I don’t know how to respond. Today on Twitter, several people have been discussing issues related to paleoclimate reconstructions. The details aren’t important for this post. What is important is one participant, Jim Bouldin, claimed people have falsely accused others of cherry-picking. He specifically mentioned Steve McIntyre, so I tried to elicit more information, asking:
The second tweet pointed out one person even used the phrase cherry-picking to describe what they had done, including a link to this post to support that claim:
I don’t have the exact words here. (I’ll edit it if I get better notes.) But, for certain, D’Arrigo put up a slide about “cherry picking” and then she explained to the panel that that’s what you have to do if you want to make cherry pie.
The other link in the tweet is to a post which showed a person said:
We strive to develop and use the best data possible. The criteria are good common low and high-frequency variation, absence of evidence of disturbance (either observed at the site or in the data), and correspondence or correlation with local or regional temperature. If a chronology does not satisfy these criteria, we do not use it. The quality can be evaluated at various steps in the development process. As we are mission oriented, we do not waste time on further analyses if it is apparent that the resulting chronology would be of inferior quality.
If we get a good climatic story from a chronology, we write a paper using it. That is our funded mission. It does not make sense to expend efforts on marginal or poor data and it is a waste of funding agency and taxpayer dollars. The rejected data are set aside and not archived.
As we progress through the years from one computer medium to another, the unused data may be neglected. Some [researchers] feel that if you gather enough data and n approaches infinity, all noise will cancel out and a true signal will come through. That is not true. I maintain that one should not add data without signal. It only increases error bars and obscures signal.
It’s difficult to imagine a more straightforward admission of cherry-picking. One person openly said you have to cherry-pick in order to make cherry pies. The other person said data which doesn’t give the expected/desired results is not kept.
Bouldin’s response to my tweets was:
Let’s check that claim. The first person I’ve referred to is Rosanne D’Arrigo. Her Columbia University profile says she works at the “Tree Ring Lab.” In fact, she’s a senior researcher at a university Tree Ring Research Laboratory. I think it’s safe to say she’s “in dendroclimatology.” The same is true for the other person I referred to, Gordon Jacoby, who previously worked at the same lab.
I could also cite the publication history of these two, or the tree ring data they’re responsible for, but I think it’s indisputable they are “in dendroclimatology.” I think it’s also indisputable one of them openly described what she had done as cherry-picking. I think it’s also quite clear this:
Fifteen years is not a delay. It is a time for poorer quality data to be neglected and not archived.
Is an admission of cherry-picking. Even if one chooses not to use some data they collect, there is no excuse for destroying that data. I think it’s obvious that is cherry-picking.
Why does Jim Bouldin deny it? I don’t know. Maybe he thinks destroying data which doesn’t give the expected/desired results is okay. Maybe, somehow, he thinks that isn’t cherry-picking. Maybe he’s just in denial and refuses to look at the links people provide to support their claims.
I don’t know, but the “denial” idea seems most likely right now. After Bouldin denied my accusation, I responded:
He didn’t respond. He kept talking on Twitter, but he ignored this tweet and a couple other tweets of mine. That’s when I began writing this post. I decided not to post this though, thinking I’d try on Twitter again in order to prevent things from escalating more than necessary. As such, I tweeted:
There was a little interlude, then Bouldin tweeted:
I don’t know how one could argue the examples I discussed in this post aren’t examples of dendroclimatologists admitting to cherry-picking. Maybe I’m missing something though. That doesn’t matter. Whether or not one agrees with my interpretation of the evidence, it is absolutely undeniable I provided that evidence.
And yet, Bouldin denied it anyway. When I pointed out his denial was silly, he tweeted:
I agreed, telling him I’d have a post up within the hour. This is it, and this is the “coherent and succinct statement of [my] position”:
That data gives an expected answer does not mean that data is correct. That data fails to give an expected answer does not mean that data is incorrect. One cannot simply ignore data which fails to give an expected answer. One certainly cannot destroy data which fails to give an expected answer so only “good” data exists.
Gordon Jacoby and Rosanne D’Arrigo openly admitted to only caring about data which gave them the results they expected. That is an open admission of cherry-picking.