Lots of meetups recently - great to see!  We hear surprisingly little about them here on LW.  Did you attend or host a meetup recently? How did it go?

Discussion article for the meetup : London

Discussion article for the meetup : London

The statistical error that just keeps on coming, Ben Goldacre, Guardian, Friday 9 September 2011 20.59 BST

We all like to laugh at quacks when they misuse basic statistics. But what if academics, en masse, deploy errors that are equally foolish? This week Sander Nieuwenhuis and colleagues publish a mighty torpedo in the journal Nature Neuroscience.

They've identified one direct, stark statistical error so widespread it appears in about half of all the published papers surveyed from the academic psychology research literature.

[...]

How often? Nieuwenhuis looked at 513 papers published in five prestigious neuroscience journals over two years. In half the 157 studies where this error could have been made, it was. They broadened their search to 120 cellular and molecular articles in Nature Neuroscience, during 2009 and 2010: they found 25 studies committing this fallacy, and not one single paper analysed differences in effect sizes correctly.These errors are appearing throughout the most prestigious journals for the field of neuroscience.

Update: Erroneous analyses of interactions in neuroscience: a problem of significance (PDF)

Update 2015-03-21: I would now strongly recommend reading Rationality: From AI to Zombies over this. Though the blog posts I collected here are the starting point for that book, considerable work has gone into selecting and arranging the essays as well as adding thoughtful new material and useful material not in this collection. Only if you've already read that should you consider starting on this; you can always skip the essays you've already read.

This is all Eliezer's posts to Less Wrong up to the end of 2010 as an EPub. Can be read with Aldiko and other eBook readers, though you might have to jump through some hoops on the Kindle (haven't tried it). I shared it privately with a few friends in the past, but I thought it might be more generally useful.  Highlights include that all the screwed-up Unicode is fixed AFAIK.

Source code.

Update: have now made a MOBI for the Kindle too.

Updated 2011-08-13 17:20 BST: Now with images!

Sorry if this seems incomplete - thought I'd fire this off as a discussion post now and hope to return to it with a more well-rounded post later.

Less Wrongers are used to thinking of uncertainty as best represented as a probability - or perhaps as a log odds ratio, stretching from minus infinity to infinity. But when I argue with people about for example cryonics, it appears most people consider that some possibilities simply don't appear on this scale at all: that we should not sign up for cryonics because no belief about its chances of working can be justified.  Rejecting this category seems to me one of the key foundational ideas of this community, but as far as I know the only article specifically discussing it is "I don't know", which doesn't make a devastatingly strong case.  What other writing discusses this idea?

I think there are two key arguments against this.  First, you have to make a decision anyway, and the "no belief" uncertainty doesn't help with that.  Second, "no belief" is treated as disconnected from the probability line; so at some point evidence causes a discontinuous jump from "no belief" to some level of confidence.  This discontinuity seems very unnatural.  How can evidence add up to a discontinuous jump - what happened to all the evidence before the jump?

Luke Parrish points me to what is clearly by far the most serious critique of cryonics ever written: a 57-page treatment by Evelina Martinenaite and Juliette Tavenier, presented as a 3rd semester project at Roskilde University in Denmark supervised by Ole Andersen.

Cryonics

December 22nd, 2010

Evelina Martinenaite, Juliette Tavenier

Abstract: The preservation of cells, tissues and organs by cryopreservation is a promising technology nowadays. However, the primary purpose of this science has been diverted to a doubtful technology, cryonics. Cryopreservation techniques are now being adapted with the aim of preserving people’s bodies after death in hope that in the future, medicine will be able to revive them. In this report we analyze both scientific and social issues involved with this technology. We first studied the events taking place in the cells during regular freezing. Various research experiments show that freezing causes damage to the cells. Therefore, vitrification presented by cryonics companies as an alternative, seems to be reasonable. We also looked at all the difficulties of this procedure and at the injuries that such a treatment could cause to the human body. Studies show that the vitrification procedure suppresses the injuries related to freezing but the use of cryoprotectants, although necessary, is toxic to the cells. Organs, such as kidneys, are the largest entities ever vitrified and thawed with success. By analyzing all present scientific data, we conclude that there is a limit to the size of living matter that can be cryonised effectively; therefore we conclude that it is not possible to cryonize an entire human body with the current technology without causing severe damage to it.

Full paper

Discussion article for the meetup : London mini-meetup

Discussion article for the meetup : London mini-meetup

Ben Best: Robert Ettinger deanimated today at around 4pm Eastern Time. He was under hospice care and had an ice bath sitting by his bedside.

Obituaries: Mike Darwin, Washington Post, Telegraph

Wikipedia

I'm going on holiday tomorrow. What freely downloadable reading do people recommend? I'm after both more serious things related to Less Wrong or SIAI/FHI's mission, or more lightweight stuff that is the sort of thing an LW participant like me would enjoy.  Thanks!

Bryan Caplan:

Mill states it well: "He who knows only his own side of the case knows little of that."  If someone can correctly explain a position but continue to disagree with it, that position is less likely to be correct.  And if ability to correctly explain a position leads almost automatically to agreement with it, that position is more likely to be correct.

[...] Put me and five random liberal social science Ph.D.s in a chat room.  Let liberal readers ask questions for an hour, then vote on who isn't really a liberal.  Then put Krugman and five random libertarian social science Ph.D.s in a chat room.  Let libertarian readers ask questions for an hour, then vote on who isn't really a libertarian.  Simple as that.

My challenge: Nail down the logistics, and I'll happily bet money that I fool more voters than Krugman.

Leah at Unequally Yoked:

Just like Caplan, I'd like to put my money where my mouth is and play in an ideological Turing Test against a Christian blogger.

UPDATE: Two Christians have contacted me to tell me they're interested.  Please suggest format ideas for us to talk over and let me know if you'd like to join in!

update to clarify: When the panel is made up of mostly genuine Blues and one or a few Greens pretending to be Blue, then the judges are all Blue.