trentmkelly/LessWrong-43k huggingface dataset:
Don't be Pathologically Mugged!
by Psy-Kosh — 2009-08-28T21:47:56.463Z

In a lot of discussion here, there's been talk about how decision algorithms would do for PD, Newcomb's Probmel, Parfit's Hitchhiker, and Counterfactual Mugging.

There's a reasonable chain there, but especially for the last one, there's a bit of a concern I've had about the overal pattern. Specifically, while we're optimizing for extreme cases, we want to make sure we're not hurting our decision algorithm's ability to deal with less bizzare cases.

Specifically, part of the reasoning for the last one could be stated as "be/have the type of algorithm that would be expected to do well when a Counterfactual Mugger showed up. That is, would have a net positive expected utility, etc..." This is reasonable, espectially given that there seems to be lines of reasoning (like Timeless Decision Theory) that _automatically_ get this right using the same rules that would get it to succeed with PD or any other such thing. But I worry about, well, actually it would be better for me to show an example:

Consider the Pathological Decision Challenge.

Omega shows up and presents a Decision Challenge, consisting of some assortment of your favorite decision theory puzzlers. (Newcomb, etc etc etc...)

Unbeknownst to you, however, Omega also has a secret additional test: If the decisions you make are all something _OTHER_ than the normal rational ones, then Omega will pay you some huge superbonus of utilions, vastly dwarfing any cost to loosing all of the individual challenges...

However, Omega also models you and if you would have willingly "failed" _HAD YOU KNOWN_ about the extra challenge above, (but not this extra extra criteria), then you get no bonus for failing everything.

A decision algorithm that would tend to win in this contrived situation would tend to lose in regular situations, right? Again, yes, I can see the argument that being the type of algorithm that can be successfully counterfactually mugged can arise naturally from a simple rule that automatically gives the right answer for many other more reasonable situations. But I can't help but worry that as we construct more... extreme cases, we'll end up with this sort of thing, were optimizing our decision algorithm to win in the latest "decision challenge" stops it from doing as well in more, for lack of a better word, "normal" situations.

Further, I'm not sure yet how to more precisely separate out pathalogical ca...
The Twin Webs of Knowledge
by Kaj_Sotala — 2009-08-28T09:45:42.067Z

Related to and partially inspired by: Joy in the Merely Real; Entangled Truths, Contagious Lies.

Where does the newborn go from here? The net is vast and infinite. -- Ghost in the Shell

There are those among us who resist the steady march of science, who feel that the reductionist creed takes away the beauty of things, who would rather enjoy sacred mysteries instead of naturalistic explanations. I suspect not many of them are reading this site. But even among aspiring rationalists, there are probably many who still feel some sympathy to that line of thought, who cannot but feel a twinge of pain where something mysterious ends up explained.
To them I reply thusly:
Picture in your mind a vast, glowing network of things, at the center of which are you. I visualize it akin to a great, vast city at night, a city that never sleeps. For some reason, all the lights in the buildings are out, so all the light comes from the myriad cars, trains and buses bustling in the night. Greg Egan's phrase, "making the pulses race along the tracks like a quadrillion cars shuttling between the trillion junctions of a ten-thousand-tiered monorail" comes to mind. Though it is not the tracks or roads themselves that we are the most interested in, but the hubs where they meet and from which they emerge.

The hubs in the network are many in kind: some are other people, some are books and items in which information is stored, some are past events and experiments once conducted. The brightest hubs are the ones closest to you, from which information is flowing to you directly: they are your glowing constellation of stars. Beyond them, the hubs glow less and less bright as they get more distant: finally they are but dim, barely visible dots in a sea of blackness, spread out like the rocks at the bottom of the seafloor. Further still, even those dots vanish, but you know it doesn't mean there aren't any: it simply means that you don't know what and where they are.
Now overlay this network of lights on a landscape. Not just the physical landscape of the Earth and the universe, though the net covers that as well. To see things in full, you must also overlay the network on the maps showing the sum of all human knowledge: that which is known in maths, physics, biology, literature, and all the sciences and arts besides. By themselves, all these landscapes are dark and impenetrable: with the gre...
Paper: Testing ecological models
by  — 2009-08-27T22:12:58.541Z

You may be interested in a paper of medium age I just read. Testing ecological models: the meaning of validation (PDF) tackles a problem many of you are familiar with in a slightly different context.

To entice you to read it, here are some quotes from its descriptions of other papers:

Holling (1978) pronounced it a fable that the purpose of validation is to establish the truth of the model…

Overton (1977) viewed validation as an integral part of the modelling process…

Botkin (1993) expressed concern that the usage of the terms verification and validation was not consistent with their logical meanings…

Mankin et al. (1977) suggested that the objectives of model-building may be achieved without validating the model…

I have another reason for posting this; I’m looking for more papers on model validation, especially how-to papers. Which ones do you consider most helpful?
Pittsburgh Meetup: Survey of Interest
by Nick_Tarleton — 2009-08-27T16:18:27.792Z

I plan to host an OBLW meetup in Pittsburgh, PA, in the next couple of weeks, but would like to know the level of interest first. Please comment if you think you'd attend.

(The planned location is a house in Squirrel Hill, about a mile and a half from Carnegie Mellon University; but if you attend CMU and would strongly prefer a location on campus, please say so.)
A Rationalist's Bookshelf: The Mind's I (Douglas Hofstadter and Daniel Dennett, 1981)
by colinmarshall — 2009-08-26T19:08:30.789Z

When the call to compile a reading list for new rationalists went out, contributor djcb responded by suggesting The Mind's I: Fantasies and Reflections on Self and Soul, a compilation of essays, fictions and excerpts "composed and arranged" by Douglas Hofstadter and Daniel Dennett. Cut to me peering guiltily over my shoulder, my own copy sitting unread on the shelf, peering back.
The book presents Hofstadter and Dennett's co-curation of 27 pieces, some penned by the curators themselves, meant to "reveal" and "make vivid" a set of "perplexities," to wit: "What is the mind?" "Who am I?" "Can mere matter think or feel?" "Where is the soul?" Two immediate concerns arise. First, The Mind's I's 1981 publication date gives it access to the vast majority of what's been thought and said about these questions, but robs it of of any intellectual progress toward the answers made in the nearly three decades since. (This turns out not to be an issue, as most of the answers seem to have drawn no closer in the 1980s, 1990s or 2000s.) Second, those sound suspiciously similar to questions hazily articulated by college freshmen, less amenable to "rational inquiry" than to "dorm furniture and bad weed." They don't quite pass the "man test," an reversal of the fortune cookie "in bed" game: simply tack "man" onto the beginning of each question and see who laughs. "Man, who am I?" "Man, where is the soul?" "Man, can matter think or feel?"
Hofstadter and Dennett's fans know, however, that their analyses rise a cut above, engaged as they are in the admirable struggle to excise the navel-gazing from traditionally navel-gazey topics. The beauty is that they've always accomplished this, together and separately, not by making these issues less exciting but by making them more so. Their clear, stimulating exegeses, explorations and speculations brim with both the enthusiasm of the thrilled neophyte and the levelheadedness of the seasoned surveyor. They even do it humorously, Hofstadter with his zig-zaggy punniness and Dennett with his wit that somehow stays just north of goofy. Thus armed, they've taken on such potentially dangerous topics as whether words and thoughts follow rules, how the animate emerges from the inanimate (Hofstader's rightly celebrated Gödel, Escher, Bach: An Eternal Golden Braid) and consciousness (most of Dennett's career), on the whole safely.
But obviously this...
Mathematical simplicity bias and exponential functions
by taw — 2009-08-26T18:34:25.269Z

One of biases that are extremely prevalent in science, but are rarely talked about anywhere, is bias towards models that are mathematically simple and easier to operate on. Nature doesn't care all that much for mathematical simplicity. In particular I'd say that as a good first approximation, if you think something fits exponential function of either growth or decay, you're wrong. We got so used to exponential functions and how convenient they are to work with, that we completely forgot the nature doesn't work that way.

But what about nuclear decay, you might be asking now... That's as close you get to real exponential decay as you get... and it's not nowhere close enough. Well, here's a log-log graph of Chernobyl release versus theoretical exponential function, plotted in log-log.

Well, that doesn't look all that exponential... The thing is that even if you have perfect exponential decay processes as with single nucleotide decay, when you start mixing a heterogeneous group of such processes, the exponential character is lost. Early in time faster-decaying cases dominate, then gradually those that decay more slowly, somewhere along the way you might have to deal with results of decay (pure depleted uranium gets more radioactive with time at first, not less, as it decays into low half-life nuclides), and perhaps even some processes you didn't have to consider (like creation of fresh radioactive nuclides via cosmic radiation).

And that's the ideal case of counting how much radiation a sample produces, where the underlying process is exponential by the basic laws of physics - it still gets us orders of magnitude wrong. When you're measuring something much more vague, and with much more complicated underlying mechanisms, like changes in population, economy, or processing power.

According to IMF, world economy in 2008 was worth 69 trillion $ PPP. Assuming 2% annual growth and naive growth models, the entire world economy produces 12 cents PPP worth of value in entire first century. And assuming fairly stable population, an average person in 3150 will produce more that the entire world does now. And with enough time dollar value of one hydrogen atom will be higher than current dollar value of everything on Earth. And of course with proper time discounting of utility, life of one person now is worth more than half of humanity millennium into the future - exponential gr...
Confusion about Newcomb is confusion about counterfactuals
by AnnaSalamon — 2009-08-25T20:01:21.664Z

(This is the first, and most newcomer-accessible, post in a planned sequence.)

Newcomb's Problem:

Joe walks out onto the square. As he walks, a majestic being flies by Joe's head with a box labeled "brain scanner", drops two boxes on the ground, and departs the scene. A passerby, known to be trustworthy, comes over and explains...

If Joe aims to get the most money, should Joe take one box or two?

What are we asking when we ask what Joe "should" do? It is common to cash out "should" claims as counterfactuals: "If Joe were to one-box, he would make more money". This method of translating "should" questions does seem to capture something of what we mean: we do seem to be asking how much money Joe can expect to make "if he one-boxes" vs. "if he two-boxes". The trouble with this translation, however, is that it is not clear what world "if Joe were to one-box" should refer to -- and, therefore, it is not clear how much money we should say Joe would make, "if he were to one-box". After all, Joe is a deterministic physical system; his current state (together with the state of his future self's past light-cone) fully determines what Joe's future action will be. There is no Physically Irreducible Moment of Choice, where this same Joe, with his own exact actual past, "can" go one way or the other.

To restate the situation more clearly: let us suppose that this Joe, standing here, is poised to two-box. In order to determine how much money Joe "would have made if he had one-boxed", let us say that we imagine reaching in, with a magical sort of world-surgery, and altering the world so that Joe one-boxes instead. We then watch to see how much money Joe receives, in this surgically altered world.
The question before us, then, is what sort of magical world-surgery to execute, before we watch to see how much money Joe "would have made if he had one-boxed". And the difficulty in Newcomb’s problem is that there is not one but two obvious world-surgeries to consider. First, we might surgically reach in, after Omega's departure, and alter Joe's box-taking only -- leaving Omega's prediction about Joe untouched. Under this sort of world-surgery, Joe will do better by two-boxing:
Expected value ( Joe's earnings if he two-boxes | some unchanged probability distribution on Omega's prediction ) ...
How does an infovore manage information overload?
by haig — 2009-08-25T18:54:32.609Z

I am, and have been for most of my life, an information glutton. The internet has made my affliction worse by providing me with the equivalent of an unlimited buffet of both nutritious as well as junk food for my brain which never leaves my side. A fire hose of data focused straight into my mind's mouth. If the brain food is mostly high quality, and I'm exercising my grey matter vigorously enough to warrant such high volumes of knowledge, then it's not that much of a problem. However, I've recently crossed a threshold where I seem to be spending more time navigating this buffet rather than consuming the food.

Ok, dropping the metaphor and getting to the point, I need to know how I can efficiently minimize the amount of time I spend staying abreast of the things I should now so I can maximizing the time I spend actually learning them and hopefully having ample time left over to be productive at applying that knowledge. Mind you, I am pretty diligent when it comes to avoiding the frivolous youtube clips, emails, and reddit/slashdot/etc. refreshes. That isn't the problem. The problem is figuring out which books, research papers, and blogs to stay aware of, and how to automate such a system. Any techniques you would like to share?
Decision theory: An outline of some upcoming posts
by AnnaSalamon — 2009-08-25T07:34:52.254Z

Last August or so, Eliezer asked Steve Rayhawk and myself to attempt to solve Newcomb’s problem together. This project served a couple of purposes:
a. Get an indication as to our FAI research abilities.
b. Train our reduction-muscles.
c. Check whether Eliezer’s (unseen by us) timeless decision theory is a point that outside folks tend to arrive at independently (at least if starting from the rather substantial clues on OB/LW), and whether anything interestingly new came out of an independent attempt.
Steve and I (and, briefly but helpfully, Liron Shapira) took our swing at Newcomb. We wrote a great mass of notes that have been sitting on our hard drives, but hadn’t stitched them together into a single document. I’d like to attempt a Less Wrong sequence on that subject now. Most of this content is stuff that Eliezer, Nesov, and/or Dai developed independently and have been referring to in their posts, but I’ll try to present it more fully and clearly. I learned a bit of this from Eliezer/Nesov/Dai’s recent posts.

Here’s the outline, to be followed up with slower, clearer blog posts if all goes well:

0. Prelude: “Should” depends on counterfactuals. Newcomb's problem -- the problem of what Joe "should" do, to earn most money -- is the problem of which type of counterfactuals best cash out the question "Should Joe take one box or two?". Disagreement about Newcomb's problem is disagreement about what sort of counterfactuals we should consider, when we try to figure out what action Joe should take.

1. My goal in this sequence is to reduce “should” as thoroughly as I can. More specifically, I’ll make an (incomplete, but still useful) attempt to:

Make it even more clear that our naive conceptions of “could” and “should” are conceptual inventions, and are not Physically Irreducible Existent Things. (Written here.)

Consider why one might design an agent that uses concepts like “could” and “should” (hereafter a “Could/Should Agent”, or “CSA”), rather than designing an agent that acts in some other way. Consider what specific concepts of “could” and “should” are what specific kinds of useful. (This is meant as a more thorou

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Value for money kills?
by KatjaGrace — 2009-08-24T23:37:59.000Z

Indonesian SODIS users (picture: SODIS Eawag)

SODIS is a cheap method of disinfecting water by putting it in the sun. Like many things, it works better in physics than society, where its effects were not significant, according to a study in PLoS medicine recently. The technical barrier is that people don’t do it much. About thirty two percent of participants in the study used the system on a given day. If you’re familiar with how little things work in reality, this is still surprising. Cheaply disinfecting water seems like it would be a hit with poor people whose children get diarrhea all the time and regularly die. Rural Bolivia, where the study was done, is a good candidate. The children studied usually get diarrhoea four times a year, which causes about fifteen percent of deaths of children under five. For the poorest quintile in Bolivia the under five death rate is about one in ten of those born alive.

The leader of the study, Daniel Mausezahl, suspects a big reason for this is that lining up water bottles on your roof shows your neighbors that you aren’t rich enough to have more expensive methods of disinfecting water. It’s hard to see from a distance the difference between chlorination and coliform-infested jerry cans, so drinking excrement can make you look better than drinking cheap clean water.

Fascinating as signaling explanations are, this seems incredible. Having live descendents is even more evolutionarily handy than impressing associates. What other explanations could there be? Perhaps adults are skeptical about effectiveness? There is apparently good evidence it works though, and there were intensive promotional campaigns during the study. What’s more, lack of evidence doesn’t usually stop humans investing in just about anything that isn’t obviously lethal in the absence of effective means to control their wellbeing. And parents are known for obsessive interest in their children’s safety. What’s going on?
Working Mantras
by Eliezer Yudkowsky — 2009-08-24T22:08:23.183Z

While working with Marcello on AI this summer, I've noticed that I have some standard mantras that I invoke in my inner dialogue (though only on appropriate occasions, not as a literal repeated mantra). This says something about which tropes are most often useful - in my own working life, anyway!

"If anyone could actually update on the evidence, they would have a power far beyond that of Nobel Prize winners."
(When encountering a need to discard some idea to which I was attached, or admit loss of a sunk cost on an avenue that doesn't seem to be working out.)

"The universe is already like [X], or not; if it is then I can only minimize the embarrassment by admitting it and adapting as fast as possible."
(If the first mantra doesn't work; then I actually visualize the universe already being a certain way, so that I can see the penalty for being a universe that works a certain way and yet believing otherwise.)

"First understand the problem, then solve it."
(If getting too caught up in proposing solutions, or discouraged when solutions don't work out - the immediate task at hand is just to understand the problem, and one may ask whether progress has been made on this. From full understanding a solution usually follows quickly.)

"Load the problem."
(Try to get your mind involved and processing the various aspects of it.)

"Five minutes is enough time to have an insight."
(If my mind seems to be going empty.)

"Ask only one thing of your mind and it may give it to you."
(Focusing during work, or trying to load the problem into memory before going to sleep each night, in hopes of putting the subconscious to work on it.)

"Run right up the mountain!"
(My general visualization of the FAI problem; a huge, blank, impossibly high wall, which I have to run up as quickly as possible. Used to accomodate the sense of the problem being much larger than whatever it is I'm working on right now.)

"When the problem is solved, that thought will be a wasted motion in retrospect."
(I first enunciated this as an explicit general principle when explaining to Marcello why e.g. one doesn't worry about people who have failed to solve a problem previously. When you actually solve the problem, those thoughts will predictably not have contributed anything in retrospect. So if your goal is to solve the problem, you should focus on the object-level problem, instead of wo

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The Journal of (Failed) Replication Studies
by Vladimir_Gritsenko — 2009-08-23T09:15:56.889Z

One of Seed Magazine's "Revolutionary Minds" is Moshe Pritsker, who created the Journal of Visualized Experiments, which to me looks like a very cool idea. I imagine that early on it may have looked somewhat silly ("he can't implant engineered tissue in a rat heart and he calls himself a scientist?!"), so it's nice to know JoVE is picking up pace.

Many folks keep pointing out how published research is itself biased towards positive results, and how replication (and failed replication!) trumps mere "first!!!11" publication. If regular journals don't have good incentives to publish "mere" (failed) replication studies, why not create a journal that would be dedicated entirely to them? I can't speak about the logistics, but I imagine it can be anything from a start-up (a la JoVE) to an open depository (a la arxiv.org).

I am not part of academia, but I understand that there are a few folks here who are. What do you say?

[EDIT: Andrew Kemendo notes two such journals in the comments: http://www.jnrbm.com/ and http://www.jnr-eeb.org/index.php/jnr.]