trentmkelly/LessWrong-43k huggingface dataset:
New paper on Bayesian philosophy of statistics from Andrew Gelman
by  — 2012-03-10T16:30:06.022Z

Andrew Gelman recently linked a new article entitled "Induction and Deduction in Bayesian Data Analysis." At his blog, he also described some of the comments made by reviewers and his rebuttle/discussion to those comments. It is interesting that he departs significantly from the common induction-based view of Bayesian approaches. As a practitioner myself, I am happiest about the discussion on model checking -- something one can definitely do in the Bayesian framework but which almost no one does. Model checking is to Bayesian data analysis as unit testing is to software engineering.
Added 03/11/12
Gelman has a new blog post today discussing another reaction to his paper and giving some additional details. Notably:

The basic idea of posterior predictive checking is, as they say, breathtakingly simple: (a) graph your data, (b) fit your model to data, (c) simulate replicated data (a Bayesian can always do this, because Bayesian models are always “generative”), (d) graph the replicated data, and (e) compare the graphs in (a) and (d). It makes me want to scream scream scream scream scream when statisticians’ philosophical scruples stop them from performing these five simple steps (or, to be precise, performing the simple steps (a), (c), (d), and (e), given that they’ve already done the hard part, which is step (b)).
Is causal decision theory plus self-modification enough? 
by Mitchell_Porter — 2012-03-10T08:04:10.891Z

Occasionally a wrong idea still leads to the right outcome. We know that one-boxing on Newcomb's problem is the right thing to do. Timeless decision theory proposes to justify this action by saying: act as if you control all instances of your decision procedure, including the instance that Omega used to predict your behavior.

But it's simply not true that you control Omega's actions in the past. If Omega predicted that you will one-box and filled the boxes accordingly, that's because, at the time the prediction was made, you were already a person who would foreseeably one-box. One way to be such a person is to be a TDT agent. But another way is to be a quasi-CDT agent with a superstitious belief that greediness is punished and modesty is rewarded - so you one-box because two-boxing looks like it has the higher payoff!

That is an irrational belief, yet it still suffices to generate the better outcome. My thesis is that TDT is similarly based on an irrational premise. So what is actually going on? I now think that Newcomb's problem is simply an exceptional situation where there is an artificial incentive to employ something other than CDT, and that most such situations can be dealt with by being a CDT agent who can self-modify.

Eliezer's draft manuscript on TDT provides another example (page 20): a godlike entity - we could call it Alphabeta - demands that you choose according to "alphabetical decision theory", or face an evil outcome. In this case, the alternative to CDT that you are being encouraged to use is explicitly identified. In Newcomb's problem, no such specific demand is made, but the situation encourages you to make a particular decision - how you rationalize it doesn't matter.

We should fight the illusion that a TDT agent retrocausally controls Omega's choice. It doesn't. Omega's choice was controlled by the extrapolated dispositions of the TDT agent, as they were in the past. We don't need to replace CDT with TDT as our default decision theory, we just need to understand the exceptional situations in which it is expedient to replace CDT with something else. TDT will apply to some of those situations, but not all of them.
[SEQ RERUN] Is Humanism A Religion-Substitute?
by MinibearRex — 2012-03-10T06:24:59.144Z

Today's post, Is Humanism A Religion-Substitute? was originally published on 26 March 2008. A summary (taken from the LW wiki):

Trying to replace religion with humanism, atheism, or transhumanism doesn't work. If you try to write a hymn to the nonexistence of god, it will fail, because you are simply trying to imitate something that we don't really need to imitate. But that doesn't mean that the feeling of transcendence is something we should always avoid. After all, in a world in which religion never existed, people would still feel that same way.

Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Amazing Breakthrough Day: April 1st, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.
Suspicious arguments regarding cow counting
by KatjaGrace — 2012-03-10T04:58:09.000Z

People sometimes think that the doomsday argument is implausible because it always says we are more likely to die out sooner than our other reasoning suggests, regardless of the situation. There’s something dubious about an argument that has the same conclusion about the world regardless of any evidence about it. Nick Bostrom paraphrases, “But isn’t the probability that I will have any given rank always lower the more persons there will have been? I must be unusual in some respects, and any particular rank number would be highly improbable; but surely that cannot be used as an argument to show that there are probably only a few persons?” (he does not agree with this view).

That this reasoning is wrong is no new insight. Nick explains for instance that in any given comparison of different length futures, the doomsday reasoning doesn’t always give you the same outcome. You might have learned that your birth rank ruled out the shorter future. It remains the case though that the shift from whatever you currently believe to what the doomsday argument tells you to believe is always one toward shorter futures. I think it is this that seems fishy to people.

I maintain that the argument’s predictable conclusion is not a problem at all, and I would like to make this vivid.

Once a farmer owned a group of cows. He would diligently count them, to ensure none had escaped, and discover if there were any new calves. He would count them by lining them up and running his tape measure along the edge of the line.

“One thousand cows” he exclaimed one day. “Fifty new calves!”

His neighbour heard him from a nearby field, and asked what he was talking about. The farmer held out his tape measure. The incredulous neighbour explained that since cows are more than an inch long, his figures would need some recalculation. Since his cows were about five foot long on average, the neighbour guessed he would need to divide his number by 60. But the farmer quickly saw that this argument must be bogus. If his neighbour was right, whatever number of cows he had the argument would say he had fewer. What kind of argument would that be?

A similar one to the Doomsday Argument’s claim that the future should always be shorter than we otherwise think. In such cases the claim is that your usual method of dealing with evidence is biased, n

...
Slowing Moore's Law: Why You Might Want To and How You Would Do It
by gwern — 2012-03-10T04:22:52.720Z

In this essay I argue the following:

Brain emulation requires enormous computing power; enormous computing power requires further progression of Moore’s law; further Moore’s law relies on large-scale production of cheap processors in ever more-advanced chip fabs; cutting-edge chip fabs are both expensive and vulnerable to state actors (but not non-state actors such as terrorists). Therefore: the advent of brain emulation can be delayed by global regulation of chip fabs.

Full essay: http://www.gwern.net/Slowing%20Moore%27s%20Law
Meetup : Madison Monday Meetup
by fiddlemath — 2012-03-10T01:29:09.258Z

Discussion article for the meetup : Madison Monday Meetup

WHEN:
12 March 2012 05:30:00PM (-0600)

WHERE:
1831 Monroe St., Madison, WI

This time around, let's see if we can find ways to be more "strategic", as in:
http://lesswrong.com/lw/2p5/humans_are_not_automatically_strategic/

I'd like to discuss this both in general ("how can we encourage strategic-ness?") and also in trying to accomplish whatever our specific goals are. ("Being more awesome" and "Making other people's lives stranger" are, surely, acceptable goals. But have we found ways to break these down into useful subgoals?)

I know we've done some of this before, but I suspect it's worth trying on a larger, more-intentional scale.

If we somehow find ourselves out of things to talk about (?!), I'll have the bits for Zendo handy.

Discussion article for the meetup : Madison Monday Meetup
How to use human history as a nutritional prior?
by CasioTheSane — 2012-03-10T00:47:58.972Z

Nutrition is a case where we have to try to make the best possible use of the data we have no matter how terrible, because we have to eat something now to sustain us while we plan and conduct more experiments.

I want to apply Bayes theorem to make rational health decisions from relatively weak data. I am generally wondering how one can synthesize historical human experiences with incomplete scientific data, in order to make risk-adverse and healthy decisions about human nutrition given limited research.

Example question/hypothesis: Does gluten cause health problems (ie exhibit chronic toxicity) in non-coeliac humans? Is there enough evidence to suggest that avoiding gluten might be a prudent risk-adverse decision for non-coeliacs?

We have some (mostly in vitro) scientific data suggesting that gluten may cause health problems in non-coeliac humans (such as these articles http://evolvify.com/the-case-against-gluten-medical-journal-references/). Let's say for the sake of arguing, that I can somehow convert these studies into a non-unity likelihood ratio for gluten toxicity in humans (although suggestions are welcome here too).

However, we also have prior information that a population of humans has been consuming gluten containing foods for at least 10,000 years, without any blatantly obvious toxic effects. Is there some way to convert this observation (and observations like this) into a prior probability distribution?
Predictability of Decisions and the Diagonal Method
by Vladimir_Nesov — 2012-03-09T23:53:28.836Z

This post collects a few situations where agents might want to make their decisions either predictable or unpredictable to certain methods of prediction, and considers a method of making a decision unpredictable by "diagonalizing" a hypothetical prediction of that decision. The last section takes a stab at applying this tool to the ASP problem.

The diagonal step

To start off, consider the halting problem, interpreted in terms of agents and predictors. Suppose that there is a Universal Predictor, an algorithm that is able to decide whether any given program halts or runs forever. Then, it's easy for a program (agent) to evade its gaze by including a diagonal step in its decision procedure: the agent checks (by simulation) if Universal Predictor comes to some decision about the agent, and if it does, the agent acts contrary to the Predictor's decision. This makes the prediction wrong, and Universal Predictors impossible.

The same trick could be performed against something that could exist, normal non-universal Predictors, which allows an agent to make itself immune to their predictions. In particular, ability of other agents to infer decisions of our agent may be thought of as prediction that an agent might want to hinder. This is possible so long as the predictors in question can be simulated in enough detail, that is it's known what they do (what they know) and our agent has enough computational resources to anticipate their hypothetical conclusions. (If an agent does perform the diagonal step with respect to other agents, the predictions of other agents don't necessarily become wrong, as they could be formally correct by construction, but they cease to be possible, which could mean that the predictions won't be made at all.)

Knowing own decision

In UDT/ADT, an agent is given definitions of its action (strategy) and utility value, and evaluates an action (strategy) by inferring the logical implications of taking it on the utility value (see this post for a more detailed description of the decision procedure and this post for an explanation of how it might be better to optimize strategy, rather than individual decisions). However, this algorithm breaks down if an agent becomes able to infer its own decision (or that a certain decision is impossible): in that case, it can infer anything from the hypothesis that it makes an impossible decision. This is one case ...
[Link, 2011] Team may be chosen to receive $1.4 billion to simulate human brain
by John_Maxwell — 2012-03-09T21:13:42.482Z

This is the team responsible for simulating the rat cortical column.

http://www.nature.com/news/2011/110308/full/news.2011.143.htm

The team is one of 6 that is being considered for at least 2 "FET Flagship" positions, which comes with all that funding. Each of the six competing teams is proposing to work on some kind of futuristic technology:

http://cordis.europa.eu/fp7/ict/programme/fet/flagship/6pilots_en.html

Of course, word on the street is that academic neuroscientists don't think much of the project:

Academic neuroscientists that I’ve ever spoken too, which is a fair number now, don’t think much of the Blue Brain project. They sometimes think it will be valuable in terms of collecting and cataloguing information about the neocortex, but they don’t think the project will manage to understand how the cortex works as there are too many unknowns in the model and even if, by chance, they got the model right it would be very hard to know that they had.

Almost all neuroscientists seem to think that working brain models will not exist by 2025, or even 2035 for that matter. What ever the date is, most consider it too far away to bother to think much about.

Such projects probably help to get more kids interested in the topic.

I think trying to influence the committee's decision potentially represents very low hanging fruit in politics as charity.

Even if academic neuroscientists don't think much of the project in its current state, it seems likely that $1.4 billion would end up attracting a lot of talent to this problem, and get us the first upload significantly sooner.

It's true that Less Wrong doesn't have a consensus position on whether to speed development of cell modeling and brain scanning technology or not. But I think if we have a discussion and a vote, we're significantly more likely than the committee to come up with the right decision for humanity. As far as I can tell, the committee will essentially be choosing at random. It shouldn't be hard for us to beat that.

Edit: But that's not to say that our estimate should be quick and dirty. In the spirit of holding off on proposing solutions, I discourage anyone from taking a firm public position on this topic for now.

In terms of avenues for influence, here are a few ideas off the top of my head:

Hire a PR agency to generate positive or negative press for a given project.

Get European L

...
New cognitive bias articles on wikipedia (update)
by nerfhammer — 2012-03-09T20:13:43.899Z

Conservatism

Curse of knowledge

Duration neglect

Extension neglect

Extrinsic incentives bias

Illusion of external agency

Illusion of validity

Insensitivity to sample size

Lady Macbeth effect

Less-is-better effect

Naïve cynicism

Naïve realism

Reactive devaluation

Rhyme-as-reason effect

Scope neglect

Also conjunction fallacy has been expanded.

(update) background

I started dozens of the cognitive bias articles that are on wikipedia. That was a long time ago. It seems people like these things, so I started adding them again.

I wanted to write a compendium of biases in book form. I didn't know how to get a book published, though.

Anyway, enjoy.
[Link] Better results by changing Bayes’ theorem
by XiXiDu — 2012-03-09T19:38:58.325Z

If it ever turns out that Bayes fails - receives systematically lower rewards on some problem, relative to a superior alternative, in virtue of its mere decisions - then Bayes has to go out the window.

-- Eliezer Yudkowsky, Newcomb's Problem and Regret of Rationality

Don't worry, we don't have to abandon Bayes’ theorem yet. But changing it slightly seems to be the winning Way given certain circumstances. See below:

In Peter Norvig’s talk The Unreasonable Effectiveness of Data, starting at 37:42, he describes a translation algorithm based on Bayes’ theorem. Pick the English word that has the highest posterior probability as the translation. No surprise here. Then at 38:16 he says something curious.

So this is all nice and theoretical and pure, but as well as being mathematically inclined, we are also realists. So we experimented some, and we found out that when you raise that first factor [in Bayes' theorem] to the 1.5 power, you get a better result.

In other words, if we change Bayes’ theorem (!) we get a better result. He goes on to explain

Link: johndcook.com/blog/2012/03/09/monkeying-with-bayes-theorem/

Peter Norvig - The Unreasonable Effectiveness of Data
Weekly LW Meetups: Atlanta, Cambridge UK, Chicago, Fort Collins, Houston, Melbourne, Twin Cities, Vancouver
by FrankAdamek — 2012-03-09T16:32:03.776Z

There are upcoming irregularly scheduled Less Wrong meetups in:

Tucson Meetup: 02 March 2012 07:00PM
University of Chicago (Again): 03 March 2012 01:46PM
Atlanta: 03 March 2012 06:30PM
Houston Meetup - 3/4: 04 March 2012 12:00PM
Vancouver!: 04 March 2012 02:00PM
Twin Cities South Metro: 06 March 2012 08:00PM
Fort Collins, Colorado Meetup Wednesday 7pm: 07 March 2012 07:00PM
Sydney - Core sequences: 13 March 2012 06:00PM
São Paulo Meetup: 14 March 2012 07:00PM
Brussels meetup: 17 March 2012 11:15AM
[Ohio/Washington DC] Interest in Reason Rally meetup?: 24 March 2012 04:14PM

The following meetups take place in cities with regularly scheduled meetups, but involve a change in time or location, special meeting content, or simply a helpful reminder about the meetup:

Melbourne practical rationality meetup: 02 March 2012 07:00PM
Cambridge UK: 04 March 2012 11:00AM
Ohio Monthly: 18 March 2012 03:00PM

Locations with regularly scheduled meetups: Austin, Berkeley, Cambridge, MA, Cambridge UK, London, Madison WI, Melbourne, Mountain View, New York, Ohio, Ottawa, Oxford, Portland, San Francisco, Seattle, Toronto, Washington, DC, Waterloo, and West Los Angeles.

If you'd like to talk with other LW-ers face to face, and there is no meetup in your area, consider starting your own meetup; it's easy (more resources here). Check one out, stretch your rationality skills, and have fun!

In addition to the handy sidebar of upcoming meetups, a meetup overview will continue to be posted on the front page every Friday. These will be an attempt to collect information on all the meetups happening in the next weeks. The best way to get your meetup featured is still to use the Add New Meetup feature, but you'll now also have the benefit of having your meetup mentioned in a weekly overview. These overview posts will be moved to the discussion section when the new post goes up.

Please note that for your meetup to appear in the weekly meetups feature, you need to post your meetup before the Friday before your meetup!

If you check Less Wrong irregularly, consider subscribing to one or more city-specific mailing list in order to be notified when an irregular meetup is happening: Atlanta, Chicago, Helsinki, London, Marin CA, Pittsburgh, Salt Lake City, Southern California (Los Angeles/Orange County area), St. Louis, Vancouver.

If y...
Political philosophy and/versus political action, not to mention arguing
by NancyLebovitz — 2012-03-09T13:44:29.337Z

I found an essay with so much good stuff in it that I was in danger of exceeding my quote quota, so I'm putting more quotes here:

"Awareness of what is first-best is a condition of being able to aim at second-best."

"What would be nice, then, would be a political philosophy that did a better job of taking this sort of typical deformation into intelligent account, which would discourage it – since it thrives on not being seen for what it is. (Also would be nice: a pony!) A theory of first-best that talks astutely about second-best. This is inherently hard to do, so I don’t say ‘theorizes well’. I guess I would propose a sort of line-of-sight rule. Optimally, you shouldn’t lose sight of your ideals or of reality. So much so obvious. But really the trick is keeping accurate score with regard to semi-idealistic philosophical and policy proposals. Philosophers like to talk about the difficulty deriving an ought from an is (or an is from an ought). But it’s equally important to think about the difficulty in analyzing an is-ought compound into component elements, the better to reduce and potentially reconstitute it."

"As philosophers, we would like to address the strongest arguments our opponents have. But this etiquette of the seminar room is bad ethics, in that this just isn’t the right approach in political philosophy. Liberalism is as liberalism does (not just as it might do, ideally). And the same goes for conservatism and libertarianism and communism and the rest. If you only address good arguments you will miss out on a perilously large proportion of your actual subject matter."

I'm not quite as sure about this one. I suppose it depends on what one means by an argument. Political philosophy presumably includes implied arguments that trying to approach some specific proposed ideal system will produce better results than not trying to approach it.