trentmkelly/LessWrong-43k huggingface dataset:
Expect to know better when you know more
by Stuart_Armstrong — 2016-04-21T15:47:20.679Z

A seemingly trivial result, that I haven't seen posted anywhere in this form, that I could find. It simply shows that we expect evidence to increase the posterior probability of the true hypothesis.

Let H be the true hypothesis/model/environment/distribution, and ~H its negation. Let e be evidence we receive, taking values e1, e2, ... en. Let pi=P(e=ei|H) and qi=P(E=ei|~H).

The expected posterior weighting of H, P(e|H), is Σpipi while the expected posterior weighting of ~H, P(e|~H), is Σqipi. Then since the pi and qi both sum to 1, Cauchy–Schwarz implies that

E(P(e|H)) ≥ E(P(e|~H)).

Thus, in expectation, the probability of the evidence given the true hypothesis, is higher than or equal to the probability of the evidence given its negation.

This, however, doesn't mean that the Bayes factor - P(e|H)/P(e|~H) - must have expectation greater than one, since ratios of expectation are not the same as expectations of ratio. The Bayes factor given e=ei is (pi/qi). Thus the expected Bayes factor is Σ(pi/qi)pi. The negative logarithm is a convex function; hence by Jensen's inequality, -log[E(P(e|H)/P(e|~H))] ≤ -E[log(P(e|H)/P(e|~H))]. That last expectation is Σ(log(pi/qi))pi. This is the Kullback–Leibler divergence of P(e|~H) from P(e|H), and hence is non-negative. Thus log[E(P(e|H)/P(e|~H))] ≥ 0, and hence

E(P(e|H)/P(e|~H)) ≥ 1.

Thus, in expectation, the Bayes factor, for the true hypothesis versus its negation, is greater than or equal to one.

Note that this is not true for the inverse. Indeed E(P(e|~H)/P(e|H)) = Σ(qi/pi)pi = Σqi = 1.

In the preceding proofs, ~H played no specific role, and hence

For all K, E(P(e|H)) ≥ E(P(e|K)) and E(P(e|H)/P(e|K)) ≥ 1 (and E(P(e|K)/P(e|H)) = 1).

Thus, in expectation, the probability of the true hypothesis versus anything, is greater or equal in both absolute value and ratio.

Now we can turn to the posterior probability P(H|e). For e=ei, this is P(H)*P(e=ei|H)/P(e=ei). We can compute the expectation of P(e|H)/P(e) as above, using the non-negative Kullback–Leibler divergence of P(e) from P(e|H), and thus showing it has an expectation greater than or equal to 1. Hence:

E(P(H|e)) ≥ P(H).

Thus, in expectation, the posterior probability of the true hypo...
Roughly you
by JDR — 2016-04-21T15:28:01.973Z

Since, like everyone, I generalise from single examples, I expect most people have some older relative or friend who they feel has added some wisdom to their life - some small pieces of information which seem to have pervasively wormed their way into more of their cognitive algorithms than you would expect, coloring and informing perceptions and decisions. For me, this would most be my grandfather. Over his now 92 years he has given me gems such as "always cut a pear before you peel it" (make quick checks of the value of success before committing to time consuming projects) and whenever someone says "that's never happened before", finishing their sentence with "said the old man when his donkey died" (just because something hasn't happened before doesn't mean it wasn't totally predictable).

Recently, though, I've been thinking about something else he has said, admittedly in mock seriousness: "If I lose my mind, you should take me out back and shoot me". We wouldn't, he wouldn't expect us to, but it's what he has said.

The reason I've been thinking of this darker quotation is that I've been spending a lot of time with people who have "lost their minds" in the way that he means. I am a medical student, and on a rotation in old age psychiatry, so have been talking to patients most of whom have some level of dementia, often layered with psychotic conditions such as intractable schizophrenia, some of whom increasingly can't remember their own pasts let alone their recent present. They can become fixed in untrue beliefs, their emotional become limited, or lose motivation to complete even simple tasks.

It can be scary. In some ways, such illness represents death by degrees. These people can remain happy and have a good quality of life, but it's certain that they are not entirely the people they once were. In fact, this is a question we have asked relatives when deciding whether someone is suffering from early dementia: "Overall, in the way she behaves, does this seem like your mother to you? Is this how your mother acts?". Sometimes, the answer is "No, it's like she is a different person", or "Only some of the time". It's a process of personality-approximation, blurring, abridging and changing the mind to create something not quite the same. What my grandfather fears is becoming a rough estimate of himself - though again, for some, that re-drawn person might be perfect...
Meetup : San Antonio Meetup
by Bryan-san — 2016-04-21T13:02:17.403Z

Discussion article for the meetup : San Antonio Meetup

WHEN:
24 April 2016 02:00:00PM (-0500)

WHERE:
818 nw loop 410 78216

Exploratory meetup to discuss rationality and all things LessWrong at Earth Burger. Earth Burger is a claimed "Upbeat fast-food joint supplying vegetarian burgers & sandwiches, with a drive-thru & vegan options".

Look for the sign that says LessWrong.

Discussion article for the meetup : San Antonio Meetup
Meetup : San Francisco Meetup: Short Talks
by rocurley — 2016-04-21T05:02:36.671Z

Discussion article for the meetup : San Francisco Meetup: Short Talks

WHEN:
25 April 2016 06:15:00PM (-0700)

WHERE:
1597 Howard St. San Francisco, CA

We'll be meeting to give/listen to short talks! You're welcome/encouraged to give a talk that you haven't prepared for, since these will be short.

Call me at 301-458-0764 to be let in.

Discussion article for the meetup : San Francisco Meetup: Short Talks
Rationality Reading Group: Part Y: Challenging the Difficult
by Gram_Stone — 2016-04-20T22:32:16.298Z

This is part of a semi-monthly reading group on Eliezer Yudkowsky's ebook, Rationality: From AI to Zombies. For more information about the group, see the announcement post.

Welcome to the Rationality reading group. This fortnight we discuss Part Y: Challenging the Difficult (pp. 1605-1647). This post summarizes each article of the sequence, linking to the original LessWrong post where available.

Y. Challenging the Difficult

304. Tsuyoku Naritai! (I Want to Become Stronger) - Don't be satisfied knowing you are biased; instead, aspire to become stronger, studying your flaws so as to remove them. There is a temptation to take pride in confessions, which can impede progress.

305. Tsuyoku vs. the Egalitarian Instinct - There may be evolutionary psychological factors that encourage modesty and mediocrity, at least in appearance; while some of that may still apply today, you should mentally plan and strive to pull ahead, if you are doing things right.

306. Trying to Try - As a human, if you try to try something, you will put much less work into it than if you try something.

307. Use the Try Harder, Luke - A fictional exchange between Mark Hamill and George Lucas over the scene in Empire Strikes Back where Luke Skywalker attempts to lift his X-wing with the force.

308. On Doing the Impossible - A lot of projects seem impossible, meaning that we don't immediately see a way to do them. But after working on them for a long time, they start to look merely extremely difficult.

309. Make an Extraordinary Effort - It takes an extraordinary amount of rationality before you stop making stupid mistakes. Doing better requires making extraordinary efforts.

310. Shut Up and Do the Impossible! - The ultimate level of attacking a problem is the point at which you simply shut up and solve the impossible problem.

311. Final Words - The conclusion of the Beisutsukai series.

This has been a collection of notes on the assigned sequence for this fortnight. The most important part of the reading group though is discussion, which is in the comments section. Please remember that this group contains a variety of levels of expertise: if a line of discussion seems too basic or too incomprehensible, look around for one that suits you better!

The next reading wil...
Meetup : Baltimore / UMBC Weekly Meetup: How To Actually Change Your Mind (part 2)
by iarwain1 — 2016-04-20T18:05:52.300Z

Discussion article for the meetup : Baltimore / UMBC Weekly Meetup: How To Actually Change Your Mind (part 2)

WHEN:
24 April 2016 03:00:00PM (-0400)

WHERE:
Performing Arts and Humanities Bldg Room 456, 1000 Hilltop Cir, Baltimore, MD 21250

Meetup is in Room 456, the philosophy department conference room. As usual, parking restrictions don't apply on weekends so park wherever you want.

We are currently going through How to Actually Change Your Mind. This week we'll be discussing Sequence G: Against Rationalization, and Sequence H: Against Doublethink.

Discussion article for the meetup : Baltimore / UMBC Weekly Meetup: How To Actually Change Your Mind (part 2)
Time hierarchy theorems for distributional estimation problems
by paulfchristiano — 2016-04-20T17:13:19.000Z

Warning: mostly for fun / basic science

##Preliminaries

Hierarchy theorems

The time hierarchy theorem is one of the simplest results in complexity theory. It says that if f(n)≫g(n), then there are functions that we can compute in time f(n) that we can't compute in time g(n). For example, there are functions that you can compute in n2 time that you can't compute in n time.

Hierarchy theorems are proved by diagonalization---consider the problem, "does machine M halt in time at most n1.5?" This problem can be easily solved in n2 time. But if any machine M solves this problem in n time then we can get a contradiction by asking M about itself.

This proof strategy is very blunt. One way to formalize its bluntness is to introduce the notion of relative complexity. Rather than considering normal computers, we consider a computer that has access to a black box computing a particular function f. Hierarchy theorems hold relative to any function f.

Relativization is a hallmark of "easy" complexity theoretic results (i.e. those that we can prove). We can prove very few separations that don't relativize. (Scott Aaronson has introduced a slightly stronger notion of algebrization which more accurately captures what we can actually prove, and we can prove a few more lower bounds on low-depth circuits.)

Distributional estimation problems

A distributional estimation problem is a sequence of distributions μn over pairs (x,y)∈{0,1}n×[0,1]. The goal of an estimator is to approximate y given x. The score of a estimator A on μn is the expected squared error, i.e. the expectation of (A(x)−y)2, for pairs (x,y) drawn from μn. If A is a probabilistic estimator, then we also take an expectation over A's internal randomness.

(This definition is due to Vadim Kosoy.)

Let's say that A is a better estimator than B on a distributional estimation problem if there is a constant ϵ and an N such that for every n>N, A's score on μn is at least ϵ higher than B's score (i.e., such that the lim inf of A's score minus B's score is strictly positive).

Time hierarchy for distributional estimation problems

Now we can ask:

Is there a distributional estimation problem μn and an estimator A running in time O(n3) such that A is a better estimator on μn than any estimator B running in time O(n2)?

The answer is almost certainly "yes," and there is a very natural hard problem---sample a machine A which runs in t

...
Meetup : Moscow: paranoid calibaration, EA criticism, deliberate practice dojo
by Slava Matyukhin — 2016-04-20T16:32:10.911Z

Discussion article for the meetup : Moscow: paranoid calibaration, EA criticism, deliberate practice dojo

WHEN:
24 April 2016 02:00:00PM (+0300)

WHERE:
Москва, Большая Дорогомиловская, 5к2

Note: most our members join meetups via other channels. Still, the correlation between "found out about Moscow meetups via lesswrong.com" and "is a great fit for our community" is very high. So we're posting just a short link to the hackpad document with the schedule here instead of the full translation of the announcement into english.

Pad with the details about 24.04.2016 meetup.

We're meeting at anticafe "Kocherga", as usual.

PS: Until and including the last meetup, we used a free donation model for these meetups. But Kocherga is still not profitable, and on the last meetup, we discussed this and decided that from now on, regular LW meetups will follow the usual payment model, i.e. 2 rubles per minute, max price 500 rubles per visit.

Discussion article for the meetup : Moscow: paranoid calibaration, EA criticism, deliberate practice dojo
Meetup : San Jose Meetup: Park Day (II)
by steven0461 — 2016-04-20T06:23:28.685Z

Discussion article for the meetup : San Jose Meetup: Park Day (II)

WHEN:
24 April 2016 03:00:00PM (-0700)

WHERE:
438 Coleman Ave, San Jose, CA 95110

The first Park Day meetup went well, so let's have a second one. You're invited to bring whatever you'd like to see at Park Day - balls, frisbees, food, etc. (Also, consider taking measures against the sun.) We'll carry a green blanket so you can recognize us. The idea is to gather outside near the listed address at the park entrance first, but probably walk elsewhere soon. If you can't find us or there's something else, please call me (Steven) at 510-6844565.

Discussion article for the meetup : San Jose Meetup: Park Day (II)
Meetup : Washington, D.C.: Fun & Games
by RobinZ — 2016-04-20T02:57:47.076Z

Discussion article for the meetup : Washington, D.C.: Fun & Games

WHEN:
24 April 2016 03:30:00PM (-0400)

WHERE:
Reynolds Center

We will be gathering in the courtyard to hang out, play games, and engage in fun conversation.

Upcoming meetups:

May 1: Utopias

May 8: Survivorship Bias

May 15: Fun & Games

Discussion article for the meetup : Washington, D.C.: Fun & Games
Gratitude Thread :-)
by Gleb_Tsipursky — 2016-04-19T03:11:19.398Z

Hi folks! Building up on the recent experiment and the #LessWrongMoreNice meme, this thread is devoted to any and all expressions of gratitude. Special rules for communication and voting apply here. Please play along!

A lot of research shows that expressing gratitude improves mental and physical health, qualities that most of us want to increase. So in this thread, please express anything you are grateful for, big or small, one-time or continuing, and feel free to post stuff that you would not normally post to Less Wrong. Encourage and support others in what they post in comments, and upvote posts that you like, while downvoting those that don't express the spirit of this thread.

If you want to discuss this thread, please do so in response to this open thread comment.

I'm grateful to you for following the spirit of this thread!
Meetup : Less Wrong New Hampshire Meetup
by Tuk — 2016-04-19T01:17:08.336Z

Discussion article for the meetup : Less Wrong New Hampshire Meetup

WHEN:
26 April 2016 07:00:00PM (-0400)

WHERE:
269 Pearl St, Manchester NH 03104

The seventeenth NH meet-up is Tuesday, 4/26, in Manchester, NH at 7 pm at a private residence. Light refreshments will be provided.

Have you read Rationality: from AI to Zombies, or any of the Sequences on Less Wrong? Maybe you're just a fan of Harry Potter and the Methods of Rationality. Come hang out with us and discuss optimization of whatever it is you want to optimize.

Agenda: Guest Host

You may want to bring a notebook.

https://www.facebook.com/events/266089027064053/

https://www.facebook.com/groups/695201067251306/

Discussion article for the meetup : Less Wrong New Hampshire Meetup
Open thread, Apr. 18 - Apr. 24, 2016
by MrMind — 2016-04-18T07:19:09.530Z

If it's worth saying, but not worth its own post (even in Discussion), then it goes here.

Notes for future OT posters:

1. Please add the 'open_thread' tag.

2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)

3. Open Threads should be posted in Discussion, and not Main.

4. Open Threads should start on Monday, and end on Sunday.
Monthly Outreach Thread
by Gleb_Tsipursky — 2016-04-17T23:18:27.584Z

Please share about any outreach that you have done to convey rationality-style ideas broadly, whether recent or not, which you have not yet shared on previous Outreach threads. The goal of having this thread is to organize information about outreach and provide community support and recognition for raising the sanity waterline, a form of cognitive altruism that contributes to creating a flourishing world. Likewise, doing so can help inspire others to emulate some aspects of these good deeds through social proof and network effects.
Does immortality imply eternal existence in linear time? 
by turchin — 2016-04-17T23:17:52.486Z

The question is important, as it’s often used as an argument against idea of immortality, on the level of desirability as well as feasibility. It may result in less interest in radical life extension as "result will be the same", we will die. Religion, on the other hand is not afraid to "sell" immortality, as it has God, who will solve all contradiction in immortality implementation. As a result, religion win on the market of ideas.

Immortality (by definition) is about not dying. The fact of eternal linear existence follows from it, seems to be very simple and obvious theorem:

“If I do not die in the time moment N and N+1, I will exist for any N”.

If we prove that immortality is impossible, then any life would look like: Now + unknown very long time + death. So, death is inevitable, and the only difference is the unknown time until it happens.

It is an unpleasant perspective, by the way.

So we have or “bad infinity”, or inevitable death. Both look unappealing. Both also look logically contradictory. "Infinite linear existence" requires infinite memory of observer, for example. "Death of observer" is also implies an idea of the ending of stream of experiences, which can't be proved empirically, and from logical point of view is unproved hypothesis.

But we can change our point of view if we abandon the idea of linear time.

Physics suggests that near black holes closed time-like curves could be possible. https://en.wikipedia.org/wiki/Closed_timelike_curve (Idea of "Eternal recurrence" of Nietzsche is an example of such circle immortality.)

If I am in such a curve, my experiences may recur after, say, one billion years. In this case, I am immortal but have finite time duration.

It may be not very good, but it is just a starting point in considerations that would help lead us away from the linear time model.

There may be other configurations in non-linear time. Another obvious one is the merging of different personal timelines.

Another is the circular attractor.

Another is a combination of attractors, merges and circular timelines, which may result in complex geometry.

Another is 2 (or many)- dimensional time, with another perpendicular time arrow. It results in a time topology. Ti...
Using humility to counteract shame
by Vika — 2016-04-15T18:32:44.123Z

"Pride is not the opposite of shame, but its source. True humility is the only antidote to shame."

Uncle Iroh, "Avatar: The Last Airbender"

Shame is one of the trickiest emotions to deal with. It is difficult to think about, not to mention discuss with others, and gives rise to insidious ugh fields and negative spirals. Shame often underlies other negative emotions without making itself apparent - anxiety or anger at yourself can be caused by unacknowledged shame about the possibility of failure. It can stack on top of other emotions - e.g. you start out feeling upset with someone, and end up being ashamed of yourself for feeling upset, and maybe even ashamed of feeling ashamed if meta-shame is your cup of tea. The most useful approach I have found against shame is invoking humility.

What is humility, anyway? It is often defined as a low view of your own importance, and tends to be conflated with modesty. Another common definition that I find more useful is acceptance of your own flaws and shortcomings. This is more compatible with confidence, and helpful irrespective of your level of importance or comparison to other people. What humility feels like to me on a system 1 level is a sense of compassion and warmth towards yourself while fully aware of your imperfections (while focusing on imperfections without compassion can lead to beating yourself up). According to LessWrong, "to be humble is to take specific actions in anticipation of your own errors", which seems more like a possible consequence of being humble than a definition.

Humility is a powerful tool for psychological well-being and instrumental rationality that is more broadly applicable than just the ability to anticipate errors by seeing your limitations more clearly. I can summon humility when I feel anxious about too many upcoming deadlines, or angry at myself for being stuck on a rock climbing route, or embarrassed about forgetting some basic fact in my field that I am surely expected to know by the 5th year of grad school. While humility comes naturally to some people, others might find it useful to explicitly build an identity as a humble person. How can you invoke this mindset?

One way is through negative visualization or pre-hindsight, considering how your plans could fail, which can be time-consuming and usually requires system 2. A faster and less effortful way is to is to imagine a per...
Weekly LW Meetups
by FrankAdamek — 2016-04-15T15:26:41.382Z

This summary was posted to LW Main on April 15th. The following week's summary is here.

New meetups (or meetups with a hiatus of more than a year) are happening in:

Nairobi mini-Meetup #1: Double Crux: 30 April 2016 03:34PM

Irregularly scheduled Less Wrong meetups are taking place in:

Ann Arbor Meetup: 16 April 2016 07:00PM
Baltimore Weekly Meetup: How To Actually Change Your Mind: 17 April 2016 03:00PM
European Community Weekend: 02 September 2016 03:35PM
Rochester (NY) Rationalists: Utopia discussion meetup: 17 April 2016 01:00PM
San Francisco Meetup: Board Games: 18 April 2016 06:15PM
Sao Paulo: 16 April 2016 02:00PM

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

Moscow social meetup: Excercises and games for rationality skills improvement: 17 April 2016 02:00PM
[Moscow] Role playing game based on HPMOR in Moscow: 23 April 2016 03:00AM
[Moscow] Games in Kocherga club: FallacyMania, Tower of Chaos, Training game: 27 April 2016 07:40PM
Sydney Rationality Dojo - May: 01 May 2016 04:00PMVienna Meetup: 16 April 2016 02:00PM
Vienna Meetup: 23 April 2016 03:00PM
Washington, D.C.: What If: 17 April 2016 03:30PM

Locations with regularly scheduled meetups: Austin, Berkeley, Berlin, Boston, Brussels, Buffalo, Canberra, Columbus, Denver, Kraków, London, Madison WI, Melbourne, Moscow, Mountain View, New Hampshire, New York, Philadelphia, Research Triangle NC, Seattle, Sydney, Tel Aviv, Toronto, Vienna, Washington DC, and West Los Angeles. There's also a 24/7 online study hall for coworking LWers and a Slack channel for daily discussion and online meetups on Sunday night US time.

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, build community, and have fun!

In addition to the handy sidebar of upcoming meetups, a meetup overview is posted on the front page every Friday. These are an attempt to collect information on all the meetups happening in upcoming weeks. The best way to get your meetup featured is still to use the Add New Meetup feature, but you'll also have the benefit of having your meetup mentioned in a weekly o...
Meetup : Washington, D.C.: What If
by RobinZ — 2016-04-15T03:40:28.986Z

Discussion article for the meetup : Washington, D.C.: What If

WHEN:
17 April 2016 03:30:00PM (-0400)

WHERE:
Reynolds Center

We will be gathering in the courtyard to discuss hypothetical scenarios.

As always, side conversations are allowed and encouraged.

Upcoming meetups:

Apr. 24: Fun & Games

May 1: Utopias

May 8: Survivorship Bias

Discussion article for the meetup : Washington, D.C.: What If