trentmkelly/LessWrong-43k huggingface dataset:
Introduction to Prisoners' Dilemma
by Scott Alexander — 2012-06-30T00:54:56.884Z

Related to: Previous posts on the Prisoners' Dilemma

Sometimes Nash equilibria just don't match our intuitive criteria for a good outcome. The classic example is the Prisoners' Dilemma.

The police arrest two criminals, Alice and Bob, on suspicion of murder. The police admit they don't have enough evidence to convict the pair of murder, but they do have enough evidence to convict them of a lesser offence, possession of a firearm. They place Alice and Bob in separate cells and offer them the following deal:

“If neither of you confess, we'll have to charge you with possession, which will land you one year in jail. But if you turn state's witness against your partner, we can convict your partner of murder and give her the full twenty year sentence; in exchange, we will let you go free. Unless, that is, both of you testify against each other; in that case, we'll give you both fifteen years.”

Alice's decision tree looks like this (note that although Alice and Bob make their decisions simultaneously, I've represented it with Alice's decision first, which is a little sketchy but should illustrate the point):

If we use the same strategy we used as a chess player, we can cross out options where Bob decides to spend extra years in jail for no personal benefit, and we're left with this:

Seen like this, the choice is clear. If you stay quiet (“cooperate”), Bob turns on you, and you are left in jail alone for twenty years, wailing and gnashing your teeth. So instead, you both turn on each other (“defect”), and end up with a sentence barely any shorter.

Another way to “prove” that defection is the “right” choice places Bob's decision first. What if you knew Bob would choose to cooperate with you? Then your choice would be between defecting and walking free, or cooperating and spending a whole year in jail - here defection wins out. But what if you knew Bob would choose to defect against you? Then your choice would be between defecting and losing fifteen years, or cooperating and losing twenty - again defection wins out. Since Bob can only either defect or cooperate, and since defection is better in both branches, “clearly” defection is the best option.

But a lot of things about this solution seem intuitively stupid. For example, when Bob goes through the same reasoning, your “rational” solution ends up with both of you in jail for fifteen years, but if you had both cooperated, you...
Meetup : Tucson: Fundamental Questions
by DeevGrape — 2012-06-30T00:51:35.867Z

Discussion article for the meetup : Tucson: Fundamental Questions

WHEN:
09 July 2012 07:00:00PM (-0700)

WHERE:
2443 North Campbell Avenue

After the moderate success of our last meetup (during which much fun and conversation was had!), there is now a next meetup. The nominal topic we'll be discussing is "the fundamental question of rationality": "What do you believe and why do you believe it?" And maybe we'll also talk about "What are you doing and why are you doing it?" Of course, discussion will veer.
Hope to see some new faces!

Discussion article for the meetup : Tucson: Fundamental Questions
Formalising cousin_it's bounded versions of Gödel's theorem
by Stuart_Armstrong — 2012-06-29T23:24:32.086Z

In this post, I'll try and put cousin_it's bounded version of Gödel's theorem on a rigorous footing. This will be logic-heavy, not programming heavy. The key unproved assumptions are listed at the bottom of the post.

Notes on terminology:

T is our deductive system.

⊥ is a canonical contradiction in T. ¬A is defined to be A→⊥.

T ⊢ A means that T proves the proposition A.

T ⊢j A means that T proves A in a proof requiring no more than j symbols.

□ A is the statement "there exists a number that is an encoding in Gödel numbering of a valid proof in T of A".

□n A is the statement "there exists a number that is an encoding in Gödel numbering of a valid proof in A with no more than n symbols in the proof".

The first needed fact is that there is a computable function g such that if T ⊢n A, then T ⊢g(n) □n A. In informal language, this means that if T can prove A in j symbols, it can prove that it can do so, in g(j) symbols. This g will be the critical piece of the infrastructure.

Now, these arguments work with general definitions of proofs, but I like to put exact bounds where I can and move uncertainty to a single place. So I will put some restrictions on the language we use, and what counts as a proof. First, I will assume the symbols "(", ")", "j", and "=" are part of the language - ( and ) as parentheses, and j as a free variable.

I will require that proofs start and end with parenthesis. A proof need not state what statement it is proving! As long as there is a computable process that can check that "p is a proof of A", p need not mention A. This means that I can make the following assumptions:

If p is a proof of A→B and q a proof of A, then (pq) is a proof of B (modus ponens).

If p is a proof of A→B and q a proof of ¬B, then (pq) is a proof of ¬A (modus tollens).

A proof that A↔B will be treated as a valid proof of A→B and B→A also.

Well-formed sentences with free variables can also have proofs (as in "j=0 or j>0" and "j>3 → j2>9").

If A and B have free variable j, and p is a proof that A→B, then (p(j=n)) is a proof that A(n)→B(n).

For a number n, l(n) is defined as the minimum number of symbols in the language of T needed to define n; generally l(n) is proportio...
Weekly LW Meetups: Berlin, Fort Collins, Montreal, NYC, Sydney
by FrankAdamek — 2012-06-29T14:10:16.796Z

There are upcoming irregularly scheduled Less Wrong meetups in:

Montreal First Meetup : 23 June 2012 01:00PM
Berlin Meetup: 26 June 2012 07:30PM
Fort Collins, Colorado Meetup Thursday 7pm *New Day*: 28 June 2012 07:00PM
First Cali, Colombia meetup: 02 July 2012 07:00PM
Hyderabad Meetup: 08 July 2012 03:00PM

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:

Summer Festival Megameetup at NYC: 23 June 2012 02:00PM
Less Wrong Sydney - June: 28 June 2012 06:30PM
Melbourne, practical rationality: 06 July 2012 07:00PM

Locations with regularly scheduled meetups: Austin, Berkeley, Cambridge, MA, Cambridge UK, Chicago, Madison WI, Melbourne, Mountain View, New York, Ohio, Oxford, Portland, Salt Lake City, Seattle, Toronto, 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, Berlin, Helsinki, London, Marin CA, Ottawa, Pittsburgh, Southern California (Los Angeles/Orange County area), St. Louis, Vancouver, Washington, DC.

If your meetup has a mailing list that you'd like mentioned here, or has become regular and isn't listed as such, let me know!

Want to help out the common good? If one of the meetups listed as regular has become inactive, let me know so we can present more accurate information to ...
Hedonic vs Preference Utilitarianism in the Context of Wireheading
by jefftk — 2012-06-29T13:50:48.261Z

We're probably going to develop the technology to directly produce pleasure in the brain with electrical stimulation. We already do this to some extent, though with the goal of restoring people to normal function. This poses a similar question to drugs, but potentially without the primary downsides: wireheading may cause intense undiminising pleasure. [1]

Like many people my first reaction to the idea is negative. Joy from wireheading strikes me as much less valuable than joy from social interaction, flow, warm fuzzies, or music. But perhaps we discount pleasure from drugs only because their overall effect on people's lives tends to be negative, and there's not actually anything lesser about that kind of happiness. If there's some activity in the brain that corresponds to the joy I value, direct stimulation should if anything be better: we can probably get much more pure, much more intense pleasure with careful application of electricity.

Maybe wireheading would grow into a role as a kind of special retirement for rich people: once you've saved enough money to pay other people to take care of your physical needs, you plug in and spend the rest of your years euphorically. Perhaps there's a cycle of increasing popularity and decreasing price. If it became cheap enough and made people happy enough, a charity to provide this for people who couldn't otherwise afford it might be more cost-effective at increasing happiness than even the best ones trying to reduce suffering elsewhere.

Even then, there's something dangerous and strange about a technology that could make people happy even if they didn't want it to. If what matters is happiness it's nearly unimportant whether someone wants to wirehead; even if they hate the idea, the harm of forcing it on them would be much less than the benefit of them being really happy for the rest of their life. Imagine it becomes a pretty standard thing to do at age 30, after fifteen years of hard work to save up the money, but a few holdouts reject wireheading and want to stay unstimulated. A government program to put wires in people's brains and pleasurably stimulate them against their will sounds like dystopic science fiction, but could it be the right thing to do? Morally obligatory, perhaps? Even after accounting for the side effect where other people are unhappy and upset about it?

Even if I accept the pleasure of wireheading as...
The Fiction Genome Project
by  — 2012-06-29T11:19:58.228Z

The Music Genome Project is what powers Pandora. According to Wikipedia:

The Music Genome Project was first conceived by Will Glaser and Tim Westergren in late 1999. In January 2000, they joined forces with Jon Kraft to found Pandora Media to bring their idea to market.[1] The Music Genome Project was an effort to "capture the essence of music at the fundamental level" using almost 400 attributes to describe songs and a complex mathematical algorithm to organize them. Under the direction of Nolan Gasser, the musical structure and implementation of the Music Genome Project, made up of 5 Genomes (Pop/Rock, Hip-Hop/Electronica, Jazz, World Music, and Classical), was advanced and codified.

A given song is represented by a vector (a list of attributes) containing approximately 400 "genes" (analogous to trait-determining genes for organisms in the field of genetics). Each gene corresponds to a characteristic of the music, for example, gender of lead vocalist, level of distortion on the electric guitar, type of background vocals, etc. Rock and pop songs have 150 genes, rap songs have 350, and jazz songs have approximately 400. Other genres of music, such as world and classical music, have 300–500 genes. The system depends on a sufficient number of genes to render useful results. Each gene is assigned a number between 1 and 5, in half-integer increments.[2]

Given the vector of one or more songs, a list of other similar songs is constructed using a distance function. Each song is analyzed by a musician in a process that takes 20 to 30 minutes per song.[3] Ten percent of songs are analyzed by more than one technician to ensure conformity with the in-house standards and statistical reliability. The technology is currently used by Pandora to play music for Internet users based on their preferences. Because of licensing restrictions, Pandora is available only to users whose location is reported to be in the USA by Pandora's geolocation software.[4]

Eminent lesswronger, strategist, and blogger, Sebastian Marshall, wonders:

Personally, I was thinking of doing a sort of “DNA analysis” of successful writing. Have you heard of the Music Genome Project? It powers Pandora.com.

So I was thinking, you could probably do something like that for writing, and then try to craft a written work with el

...
[SEQ RERUN] The Genetic Fallacy
by MinibearRex — 2012-06-29T05:06:25.645Z

Today's post, The Genetic Fallacy was originally published on 11 July 2008. A summary (taken from the LW wiki):

The genetic fallacy seems like a strange kind of fallacy. The problem is that the original justification for a belief does not always equal the sum of all the evidence that we currently have available. But, on the other hand, it is very easy for people to still believe untruths from a source that they have since rejected.

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 My Kind of Reflection, 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.
Scholarship: how to tell good advice from bad advice?
by ChrisHallquist — 2012-06-29T02:13:01.306Z

Lukeprog has done some great posts talking about how scholarship has benefited him personally and how to do it. However, he hasn't talked much about how to tell the good from the bad, and I think this is an especially big problem with it comes to "how to"s, rather than standard academic subjects.

The thing is this: writing on academic subjects tends to be dominated by academics seeking to gain status from their work. Not all fields have a strong correlation between status and making actual discoveries, but many (perhaps most) do. So for academic subjects, the big challenge when it comes to making sure you're not reading nonsense is to try to evaluate the soundness of the field in question.

When it comes to seeking out "how to" advice, though, writing on the subjects seems to be dominated by people looking to make money selling advice. That means that if bad advice will sell better than good advice, they'll give the bad advice. Even if their writing includes legitimate advice, they have incentives to give a distorted picture of the subject they're writing on if it will sell better (for example, making whatever they're talking about sound easier than it really is). In some cases, advice books end up trying to nudge you towards buying some more expensive thing the author is selling.

So: when you're researching a "how to" topic, how do you tell the good advice from the bad advice?
Nash Equilibria and Schelling Points
by Scott Alexander — 2012-06-29T02:06:13.524Z

A Nash equilibrium is an outcome in which neither player is willing to unilaterally change her strategy, and they are often applied to games in which both players move simultaneously and where decision trees are less useful.

Suppose my girlfriend and I have both lost our cell phones and cannot contact each other. Both of us would really like to spend more time at home with each other (utility 3). But both of us also have a slight preference in favor of working late and earning some overtime (utility 2). If I go home and my girlfriend's there and I can spend time with her, great. If I stay at work and make some money, that would be pretty okay too. But if I go home and my girlfriend's not there and I have to sit around alone all night, that would be the worst possible outcome (utility 1). Meanwhile, my girlfriend has the same set of preferences: she wants to spend time with me, she'd be okay with working late, but she doesn't want to sit at home alone.

This “game” has two Nash equilibria. If we both go home, neither of us regrets it: we can spend time with each other and we've both got our highest utility. If we both stay at work, again, neither of us regrets it: since my girlfriend is at work, I am glad I stayed at work instead of going home, and since I am at work, my girlfriend is glad she stayed at work instead of going home. Although we both may wish that we had both gone home, neither of us specifically regrets our own choice, given our knowledge of how the other acted.

When all players in a game are reasonable, the (apparently) rational choice will be to go for a Nash equilibrium (why would you want to make a choice you'll regret when you know what the other player chose?) And since John Nash (remember that movie A Beautiful Mind?) proved that every game has at least one, all games between well-informed rationalists (who are not also being superrational in a sense to be discussed later) should end in one of these.

What if the game seems specifically designed to thwart Nash equilibria? Suppose you are a general invading an enemy country's heartland. You can attack one of two targets, East City or West City (you declared war on them because you were offended by their uncreative toponyms). The enemy general only has enough troops to defend one of the two cities. If you attack an undefended city, you can capture it easily, but if you attack the city with the e...
Meetup : A Game of Nomic
by alyssavance — 2012-06-29T00:49:38.820Z

Discussion article for the meetup : A Game of Nomic

WHEN:
21 July 2012 03:00:00PM (-0400)

WHERE:
Midtown Manhattan, New York, NY 10010

Hi everyone. I'll be holding a Saturday meetup at my apartment to play Nomic, not this Saturday, but next Saturday (July 7th, nine days from now). For those not familiar with Nomic, it's a game where playing the game is about changing the rules of the game. The last time we played with the NYC rationalist group was super-awesome, and I'm looking forward to doing it again.

Meetup will start at 3 PM, and will be followed by pizza or other forms of dinner (depending on interest).

NOTE: Due to conflict with other events, this has been moved to Saturday, July 21st.

Discussion article for the meetup : A Game of Nomic
Call for volunteers: Publishing the Sequences
by wedrifid — 2012-06-28T15:08:39.443Z

The Singularity Institute is in the process of publishing Eliezer Yudkowsky’s Sequences of rationality posts as an electronic book. The Sequences are made up of multiple hundreds of posts. These are being downloaded and converted to LaTeX for publishing programmatically and that’s where the human tasks begin. These will entail:

Verifying that all the content has all been transferred, including all text, equations and images.

Proofreading for any typographical errors that may have escaped attention thus far.

Verifying that all external links are still alive (and replacing any that are not).

Creating a bibliography for all material referenced in the chapters (posts).

The recent document publishing efforts at SIAI would not have been possible without the assistance of dedicated volunteers. This new project is the perfect opportunity to help out lesswrong while giving you an excuse to catch up on (or revisit) your reading of some foundational rational thinking material. As an added bonus every post reviewed will save the world with 3.5*epsilon probability.

We need volunteers who are willing to read some sequence posts and have an eye for detail. Anyone interested in contributing should contact me at cameron.taylor [at] singinst [dot] org.

For those more interested in academic papers we also have regular publications (and re-publications) that need proofreading and editing before they are released.
Meetup : St. Peterburg meetup
by Yuu — 2012-06-28T06:33:14.976Z

Discussion article for the meetup : St. Peterburg meetup

WHEN:
05 July 2012 07:00:00PM (+0400)

WHERE:
Russia, Saint Petersburg, Nevsky Prospect 20

We will meet at “Subway” restaurant at 19:00. Look for a table with “LW” banner, I will put it somewhere.

Topics will be:

Rationality in everyday life and in fiction.

Transhumanism movement in Russia.

Projects to begin by rationalists commumity.

Please comment here, if you are going to participate.

Discussion article for the meetup : St. Peterburg meetup
Help create an instrumental rationality "stack ranking"?
by Elliot_Olds — 2012-06-28T06:06:24.237Z

I recently heard about SIAI's Rationality Minicamp and thought it sounded cool, but for logistical/expense reasons I won't be going to one.

There are probably lots of people who are interested in improving their instrumental rationality, know about and like LessWrong, but haven't read the vast majority of content because there is just so much material, and the practical payoff is uncertain.

It would be cool if it was much easier for people to find the highest ROI material on LessWrong.

My rough idea for how this new instrumental rationality tool might work:

It starts off as a simple wiki focused on instrumental rationality. People only add things to the wiki (often just links to existing LessWrong articles) if they have tried them and found them very useful for achieving their goals.

People are encouraged to add "exercises" that help you develop the skill represented by the article, of the type that are presumably done at the Rationality Minicamps.

Only people who have tried the specific thing in question should add comments about their experiences with it.

Long Term Goal: Every LessWrong user can define their own private stack rank of the most important concepts/techniques/habits for instrumental rationality. These stack ranks are globally merged by some LessWrong software to create an overall stack rank of the highest ROI ideas/behaviors/techniques as judged by the LessWrong community at any given time. People looking to improve their instrumental rationality can then just visit this global stack rank and pick the highest item that they haven't tried yet to experiment with, and work backwards from there if there are any prerequisites.

Do you think others would find this useful? Anyone have suggested improvements?
[SEQ RERUN] My Kind of Reflection
by MinibearRex — 2012-06-28T04:28:52.384Z

Today's post, My Kind of Reflection was originally published on 10 July 2008. A summary (taken from the LW wiki):

A few key differences between Eliezer Yudkowsky's ideas on reflection and the ideas of other philosophers.

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 The Fear of Common Knowledge, 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.