Friday, December 09, 2005

My First Post

I finally got around to starting a blog today for two unrelated reasons. The first was coming across a speech by Michael Crichton deploring the victory of politics over science in the form of "consensus science." One of his examples ...

"
According to Sagan and his coworkers, even a limited 5,000 megaton nuclear exchange would cause a global temperature drop of more than 35 degrees Centigrade, and this change would last for three months. The greatest volcanic eruptions that we know of changed world temperatures somewhere between .5 and 2 degrees Centigrade. Ice ages changed global temperatures by 10 degrees. Here we have an estimated change three times greater than any ice age. One might expect it to be the subject of some dispute.

But Sagan and his coworkers were prepared, for nuclear winter was from the outset the subject of a well-orchestrated media campaign. The first announcement of nuclear winter appeared in an article by Sagan in the Sunday supplement, Parade. The very next day, a highly-publicized, high-profile conference on the long-term consequences of nuclear war was held in Washington, chaired by Carl Sagan and Paul Ehrlich, the most famous and media-savvy scientists of their generation. Sagan appeared on the Johnny Carson show 40 times. Ehrlich was on 25 times. Following the conference, there were press conferences, meetings with congressmen, and so on. The formal papers in Science came months later.

This is not the way science is done, it is the way products are sold."

I formed my own opinion on that particular issue many years ago, after reading a scientific article by the authors of one of the articles that fed into the nuclear winter calculations. It conceded that their earlier article contained, as critics had pointed out, a serious error--serious enough so that correcting it reduced the predicted duration of global winter from years to weeks. But they explained that they had now discovered another error in the opposite direction--and correcting it brought the duration back to years.

My guess is that they were telling the truth about their analysis. They may even have been correct in their conclusion. But the degree of uncertainty implied by that article was strikingly inconsistent with the confidence with which the nuclear winter conclusion was being trumpeted--largely by people who wanted other people to believe it because they thought that belief would reduce the risk of nuclear war.

[All of this was long ago and I am working from memory, so if you want to check my report of the article I am afraid you will have to locate it for yourself.]

My second reason to start a blog was a recent experience of the virtues of Chicago style workshops.

At most universities, if you are invited to give a paper, you get something like an hour and a half, most of which is spent reading your paper aloud--on the bizarre theory that the professors and graduate students who make up your audience are unable to read it for themselves. Any remaining time can be spent answering questions from people most of whom have just heard your ideas for the first time.

Many years ago, someone at the University of Chicago came up with a better model. At a Chicago style workshop, everyone is expected to read the paper in advance. The author gets fifteen minutes to half an hour--the time increases the farther you are from Chicago--to say whatever he wants about his paper. After that it is open season, with members of the audience pointing out errors, raising questions, suggesting ways in which the paper might be expanded or improved. Great fun for all, and the nearest thing I have observed to real time thinking by a group brain.

Recently I observed a striking demonstration of the superiority of the Chicago workshop. I was attending one--not at Chicago. Reading the paper, I noticed a mistake in the brief theoretical section that was supposed to motivate the conjecture tested in the statistical analysis that was the core of the paper. The authors had left a term out of an equation--had assumed, in effect, that when A sues B and wins, B pays damages but A does not receive them. Correcting that mistake, and changing nothing else, reversed the conclusion--implied that the conjecture they were testing could not be true. To restore the conclusion it was necessary to make additional changes, dropping one or another of the simplifying assumptions that had gone into the model. The mistake was sufficiently obvious so that any competent graduate student in the field who actually worked his way through the paper should have spotted it.

Before the talk started, I mentioned the existence of the mistake to one of the authors. Shortly thereafter, another professor came in--and also described the mistake to him. A few minutes after the talk started a third member of the audience, a very distinguished senior member of our profession, raised his hand and pointed out that the model was clearly wrong.

What struck me was not the existence of a careless error in an unpublished draft of a scholarly article--we all make mistakes. What struck me was that this was not the first university the paper had been presented at. Presumably, none of the others followed the Chicago model. If your first contact with a paper is an oral presentation, you are unlikely to check the details of the equations. Apparently nobody at those talks had.

[To be fair, I should add that the author told me that the error had been mentioned to him, although not explained, on one earlier occasion--but not by someone whose first exposure to the work was at a university talk.]


12 Comments:

At 3:46 AM, December 14, 2005, Blogger Bevo said...

Great! That you are here! :-)
Bevo (from Germany)

www.freiheitsachse.blogspot.com

 
At 8:49 PM, December 14, 2005, Blogger Milhouse said...

Automatic trackback seems either not to be working, or to be slow, so here's a ping.

 
At 5:42 AM, December 17, 2005, Blogger Scott said...

Welcome to the blogosphere, Professor--wonderful to see you.

 
At 8:19 PM, December 17, 2005, Anonymous Roderick T. Long said...

Hi, great to see you're blogging!

On the topic of presenting papers, let me put in a plug for the Auburn Model, i.e., the way we do it in the Auburn philosophy dept.

It's like the Chicago model in that everyone (or everyone who's interested) reads a copy of the paper in advance. The advantages of this are precisely those you mention.

But it's unlike the Chicago model in that the presenter then reads the paper before discussion rather than just "talking through it." The advantage of this is that it refreshes the memory of those who read the paper (as well, of course, as bringing up to speed those who didn't get a chance to read it). Another advantage is that philosophy papers often get rather technical and often there is no way to simply "talk through it" without blurring the crucial distinctions.

 
At 12:49 PM, December 18, 2005, Blogger David Friedman said...

Roderick Long offers a plug for a modified version of the Chicago Model, but I am unconvinced. If you spend an hour reading the paper instead of fifteen minute talking about it, that's forty-five minutes less for the participants to discuss the paper--and forty-five minutes more for those who read the paper to be punished for doing so, and get bored. Once everyone has observed the consequence of reading the paper in advance, you are back with the conventional model, where listening replaces reading.

So far as blurring crucial distinctions, that's easier to avoid in a written paper. And in the Chicago Model, you can spend your fifteen minutes on explaining precisely those points that you think readers of the paper might have misunderstood.

 
At 3:05 PM, December 19, 2005, Anonymous Pete Bessman said...

Ah, props to the man who taught me to use the endash --- or whatever the appropriate term is --- when serial commas get boring.

\m/ (>.<) \m/

Rock on.

 
At 5:11 PM, December 19, 2005, Blogger Rafe said...

The practice of reading the full text of papers that people are holding in their hands beggars the imagination but it happened three times in a row at the Popper session of the Christchurch Mont Pelerin Society meeting in 1989. Christchurch is the place where Popper wrote The Open Society and its Enemies (1945). I will not name the culprits but one after the other they placed their texts on the lectern and presented the tops of their heads to the audience for about 50 minutes each. It was the afternoon session and the monotony plus the sun from the windows on the western wall proved too much for many of the not young libertarians (on top of a little wine at lunch). Sowell and Buchanan were absent, possibly sampling wine elsewhere in the hinterland.

The appropriate procedure under those circumstances is surely to speak to your paper, especially relating your main points to the themes of the conference and to significant points raised in other papers on the program. This is what I tried to do in the "commentary" paper which had already been written and circulated.

I take Rod's point if the paper is both original and technical, more time could be allocated to the major argument of the paper. However out of many hundreds of conference papers that I have encountered there are very few that are sufficiently original to deserve to be read right through.

 
At 1:12 PM, December 22, 2005, Blogger Eric H said...

Finally! Welcome, and please feel free to make the blogosphere as entertaining as you did Usenet.

 
At 7:53 PM, December 23, 2005, Blogger Eric said...

Another advantage of the Chicago style workshop is that if the paper is fatally flawed, as in the example described in the post, the workshop can still be useful and entertaining. The paper can be tossed aside, and the audience and author can talk about how to write a better paper on the same subject.

 
At 7:57 PM, December 23, 2005, Blogger M.C. said...

Very interesting post.

"Consensus science" is all about the sociology of human beliefs. That's a major subject of my blog.

 
At 11:31 PM, February 01, 2006, Anonymous Francis said...

Hi, Mr. Friedman;

it struck me as amazing that what you call "the Chicago model" was almost unique in the academic research circles. In the private R&D industry, I must say it is the only model I ever saw! To be more precise, when an engineer or scientist submits a design or substantial idea to the team, then (1) everyone reads the document beforehand, then a meeting is called where(2)the author "walks through" the document by naming each section and asking for comments/corrections at each step. The author corrects the document in some companies, a second iteration is done. The process rarely fails to identify mistakes.

Perhaps the goal of most academic colleges is not to catch mistakes as early as possible, but to publish as early as possible? Seems likely to me...

 
At 11:40 PM, February 10, 2006, Blogger David Friedman said...

I don't know if anyone is still looking at this post, which was the first one on the blog. But I just came across a post going into a little more detail on the case of Sagan and Nuclear Winter. It's at:

http://www.chicagoboyz.net/
archives/003931.html

(unwrap before using)

 

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