Still More to the Prisoner's Dilemma
After reading http://www.pnas.org/content/early/2012/05/16/1206569109.full.pdf+html , the detail that's caught my attention: "The player with the shortest memory sets the terms of the game." If a strategy remembers 0 turns, and simply Always Cooperates, or Always Defects, or randomly chooses between them, then no matter how clever its opponent might be, it can't do any better than by acting as if it were also a Memory-0 strategy. Tit-for-Tat is a Memory-1 strategy - and despite all the analysis that I've read on it before, I now see it from a new perspective, in that it's one of the few Memory-1 strategies that gracefully falls back to the appropriate Memory-0 strategy when faced with All-C or All-D... and any strategy which tries to implement a more complicated scheme based on longer strings is faced with the fact that Tit-for-Tat simply doesn't remember anything beyond a single turn.
I would like to see if this perspective can be extended to a Memory-2 strategy that falls gracefully back to appropriate Memory-1 strategies such as Tit-for-Tat when faced with Memory-1 strategies, and like Tit-for-Tat, to a suitable Memory-0 strategy when faced with Memory-0 ones.
Does anyone have a link to a suitable set of programs to run some experimental tourneys, and instructions on how to apply them? (If it matters, the OSes I have available are WinXP and Fedora 21.)
This is a neat question, but I think programs being successful is not really about gracefully going down a hierarchy. For example, Tit-for-Tat does not take the correct strategy against always-cooperate (If your opponent is always cooperating, you say thank you and always defect). Tit-for-Tat succeeds for much more ecological reasons. I'd say bigger-memory versions of Tit-for-Tat are going to be something like the class of "peaceful, non-exploitable" strategies. Such strategies are not going to be the first to defect, which means they actually don't get that much information about their opponent. I think the lesson of iterated prisoners dilemmas is that you don't need that information anyhow, as long as your strategy occupies a good ecological niche.
There's still some subtlety here. A Memory-0 strategy picks C with probability p and D with probability q, independent of any past results. If you know p and q, you can devise a strategy to optimize your score. The result in the paper is that this new strategy is Memory-0 and that you can't do better by increasing your memory.
The advantage of a longer memory is that, given enough iterations, you can get a good approximation for p and q and so deduce the appropriate Memory-0 strategy. Something like Tit-for-Tat is devised to basically get the same score as its opponent (the opponent can get an advantage of one defection). It's not going to do worse than any individual opponent, but neither is it going to do better. A strategy that remembers the entire game can recognize, say, All-C and exploit it by defecting, which Tit-for-Tat can't do.
A Memory-1 strategy is one where p and q are functions of the previous round. In general, they'll depend both on what it did last round and what the opponent did last round. There are four possible results (C-C, C-D, D-C, D-D), which means that the strategy will have up to four distinct probabilities for cooperation next round. If you can learn those...
I managed to get my Bayes RPG into such a state that, although it still isn't that interesting as a game, it's moderately entertaining for a brief while until you master it, and seems like it should produce some actual learning.
I had this game as my MSc thesis topic as a way to force myself to work on the game, but I'm now finally starting to get to the point where a) working on it is fun enough that I don't need an external motivator b) I'd like to actually graduate. So I'll take what I have so far, run it to a bunch of test subjects, see if they learn anything, and write up the results in my thesis. Then I'll continue working on the game on my spare time.
But I'd like to do the empirical part of the thesis properly. Since LW has a bunch of people who know a lot about statistics, I'd like to ask LW: what kinds of statistical tests would be most appropriate for measuring the results?
To elaborate more on the test setup. I expect to go with the standard approach: have some task that measures understanding of something that we want the game to teach, and split people into an intervention group and control group. Have them complete the task first, dropping anyone who does too well in th...
I sometimes come across an interesting scientific paper where the study being done seems easy and/or low-budget enough to make me think "hey, I could do that" (on this occasion, this paper on theanine levels in tea, which I skimmed too quickly the first time to notice that they used big, proper and presumably expensive lab equipment to measure it because I was reading it for practical reasons (reading about modafinil amplifying the side-effects of caffeine, while beginning an all-nighter powered by those chemicals)), and to me there's a strong "coolness factor" to being someone who's published real research, especially if that also means a finite Erdos number. How easy/difficult is it to become author or co-author of a scientific paper as an amateur, given that you're trying to actually accomplish something and not munchkin for "get my name published as easily as possible"?
Unrelatedly, I'm pretty sure posting under the influence of caffeine and modafinil is a terrible idea for me. I just spent two hours writing and re-writing that question, and I'm only stopping now because I'm giving up on trying to get it right. That's only exacerbating a tendency I already have, but damn.
The risks of one-time MDMA use can be roughly sorted into two categories: "Normal Risks" which apply to everyone and "Edge-Case Risks" which only apply to certain people (though it may not always be clear, as we will see, if you are at risk for one of the edge-cases). I will give a very brief and oversimplified description of how MDMA is processed by the body and the effects it has, and then I will describe some of these risks. I didn't have time to put together sources and citations (especially as this was written from memory + fact checking), but my hope is that this will help people understand what the risks are and some of the mechanisms of action so that they can do more informed research into the topic.
Basic Neuroscience Background Information
In the human brain, where two neurons meet is called the Synapse. In reality, there is actually a small gap at the synapse between neurons called the synaptic cleft. When a signal traveling down a neuron reaches the end, it causes a release of neurotransmitters into the synaptic cleft. These neurotransmitters fit like keys into keyholes called receptors on the second neuron. Depending on which keyholes/receptors are ...
Part 2
Macro-Level Physiological Effects
The increase in Dopamine, Norepinephrine, and Serotonin caused by MDMA causes Central Nervous System (CNS) stimulation that can raise body temperature, heart rate, and blood pressure. It can also cause increased sweating and perspiration, insomnia, nausea, and diarrhea, all of which contribute to dehydration. These comprise Normal Risk #2 family. The fact that MDMA use is often associated with excessive dancing, hot environments, and limited access to water and electrolytes (such as at raves, music festivals, concerts, etc.) compounds these risks. So, if a person has no cardiovascular issues, is mindful of these risks, stays hydrated, ensures not to drink too much water without electrolytes, and keeps their heart rate and body temperature in check, most of these risks can be avoided. However, for anyone with cardiovascular issues (even ones they don't know about) this becomes Edge-Case Risk #3
Other/Unknown-Mechanism Psychological Effects
MDMA is a psychotropic drug. As such, it has the possibility of triggering latent psychological disorders such as Bipolar Disorder, Depression, epilepsy, and Schizophrenia just the same way that LSD, emotional...
I've intentionally been getting 45-90 minutes of daily sun and it feels good. Where can I find a good cost-benefit calculation for natural sun exposure vs. dietary vitamin D supplementation without sun? (Presumably mostly weighing cancer risk against vitamin d / nitric oxide / other benefits of natural sun?).
Bonus points if darker skin tones are taken into consideration.
I don't quite understand gratitude journaling. First of all, gratitude is the same thing as gratefulness or thankfulness, right? If yes, it means, you are glad because you got stuff you did not really earn, you got stuff that was not yours by right, was not owed to you, right? Because when a debt is paid or you get paid for your work, you don't feel grateful, this is yours by right.
So to me gratitude journaling seems to drive your focus on the things you got without earning them. Is that supposed to help people who have self-esteem problems? SSC wrote how most depressed people feel like a burden, how the heck does feeling grateful for things one does not really earn or deserve make one feel less of a burden?
What am I missing here?
If anything, I would experiment with achievement journaling.
Because when a debt is paid or you get paid for your work, you don't feel grateful, this is yours by right.
That sounds like a deeply unsatisfying way to live; it seems like you will mostly be disappointed by the things that are "yours by right" that you don't get.
The point of gratitude journaling is to focus on how your life has many good things in it. "I got my paycheck for the hours I worked this week; I'm thankful that my employer is honest and prompt, I'm thankful that I have a job, I'm thankful that past-me put in the effort to develop skills relevant to this job, I'm thankful that I live within my means..." and so on. This might involve lowering your expectations so that actually being paid is remarkable enough to write down.
This might involve lowering your expectations so that actually being paid is remarkable enough to write down.
In general that's done by setting a target of at least 3 things to write down every day, so you just pick the best ones.
I’m a fourth year PhD student in the life sciences, and I need mentorship, preferably from a Slytherin, or at least someone with a Slytherin hat. My advisor doesn’t want me doing “mercenary collaborations”, or quick experiments with researchers outside my field in exchange for secondary authorships. He says I need to focus on my thesis research in the next year so as to publish and graduate. Are there any academics in the LW readership who have the insight to tell me whether this is good advice or whether he just wants me pumping out papers with his name on them so he can get tenure?
Disclaimer: this thought is "foxy", in the sense that I don't assert it's definitively true, but I still think it could be a useful lens for viewing the world.
Startups Don't Create New Technology
Contra gurus like Paul Graham and Peter Thiel, successful tech startup companies do not actually create new technology. Good tech startups do one of two things: 1) invent a new technology-dependent business model, or 2) repackage and polish existing technology in such a way as to bring it above the threshold for widespread use.
Consider a couple of recen...
To add a bit of empirical analysis to this comment, I analyzed the YCombinator Winter 2015 batch. I categorized the startups into one of three buckets: Tech-Dependent Business Model (TDBM), RePackaging and Polishing existing tech (RPP), and Novel Tech (NT). The list can be found here.
I want to invest $10,000 in a stock index fund. (The money is currently in a checking account.) How do I actually go about doing this?
I'm looking for a book, or a combination of up to 5 books, that fulfills the following requirements:
The first time I read the Sequences, I definitely didn't understand everything. And of the things I did "understand", I didn't remember them all. Even after rereading different posts, it doesn't always stick.
I have just come across the brilliant idea (sarcasm) to take notes. In particular, to try to boil each post down to its essence, and write a summary. I've done it for about 20 posts so far, and it seems to be really helping me understand stuff.
Furthermore, the act of having "conquered" a post (having had boiled it down to its essenc...
My mom has multiple sclerosis. Recently, researchers found that two currently available drugs reverse de-myelinization in mice. The drugs are only approved for being applied to the skin, though - it hasn't been proven to regulator's standards that they're safe for humans to swallow or inject.
Can anything be done to take advantage of this other than "sit and wait for years while Medical Science does more research"?
Has the company shut down?
Yes. It would be helpful if they did a public postmortem, but I'm not sure there's a way to do that that's not ugly.
In the Sleeping Beauty problem, SIA and SSA disagree on the probability that it's Monday or Tuesday. But if we have to bet, then the optimal bet depends on what Ms Beauty is maximizing - the number of bet-instances that are correct, or whether the bet is correct, counting the two bets on different days as the same bet. Once the betting rules are clarified, there's always only one optimal way to bet, regardless of whether you believe SIA or SSA.
Moreover, one of those bet scenarios leads to bets that give "implied beliefs" that follow SIA, and the ...
I have been thinking about politics again, this time from a meta level and considering motivations for positions.
Among my peer group and much of the media, the dominant model seems to be 'anyone who has center-right views is consumed by hate and/or a useful idiot for the evil ones, and anyone who has further right views is a jackbooted fascist'.
Now, given that the views they cannot tolerate are nothing compared to the NRxers, in a way this strikes me as absurd hysteria. But in another way this makes sense (except for the overreaction). I don't think most p...
The problem is that the experiment likely didn't prove it.
Yes, it is true that there are massive problems in failure to replicate in psychology, not to mention bad statistics etc. However, a single experiment is still evidence in favour.
Then the reporter overstate the results
Actually, the reporter understated the results, for instance by including this quote from an academic who disgrees:
“There is absolutely no reason to expect that women's hormones affect how they vote any more than there is a reason to suggest that variations in testosterone levels are responsible for variations in the debate performances of Obama and Romney,” said Susan Carroll, professor of political science and women's and gender studies at Rutgers University, in an e-mail.
Carroll sees the research as following in the tradition of the “long and troubling history of using women's hormones as an excuse to exclude them from politics and other societal opportunities.”
Thing is, Prof. Carroll is not a neuroscientist. So what gives her the right to tell neuroscientists that they are wrong about neuroscience?
Seeking Moore's Law extrapolations
I once found some charts showing a few close variants of Moore's Law, such as MIPS per dollar per year; but I seem to have lost them. Does anyone have some references handy, which I can mine for some SFnal worldbuilding? (Eg, how big and costly a device storing 100 petabytes would be in a given year.)
I've done some rather extensive investigations into the physical limits of computation and the future of Moore's Law style progress. Here's the general lowdown/predictions:
Moore's law for conventional computers is just running into some key new asymptotic limits. The big constraint is energy, which is entirely dominated now by interconnect (and to a lesser degree, passive leakage). For example, on a modern GPU it costs only about 10pJ for a flop, but it costs 30pJ just to read a float from a register, and it gows up orders of magnitude to read a float from local cache, remote cache, off-chip RAM, etc. The second constraint is the economics of shrinkage. We may already be hitting a wall around 20nm to 28nm. We can continue to make transistors smaller, but the cost per transistor is not going down so much (this effects logic transistors more than memory).
3D is the next big thing that can reduce interconnect distances, and using that plus optics for longer distances we can probably squeeze out another 10x to 30x improvement in ops/J. Nvidia and Intel are both going to use 3D RAM and optics in their next HPC parts. At that point we are getting close to the brain in terms of a l...
Is transcranial direct current stimulation technology yet at the point where someone who starts it has higher expected gains than costs? I.e., should more LWers be using it? You can comment and/or answer this poll:
Do you think the average LWer would get a net benefit from using tDCS, taking into account the benefits, costs of equipment, risks, etc.? [pollid:906] How much do you know about this topic? [pollid:907]
It is interesting to watch how different things I observe on internet interact with each other. Two recent discoveries:
1) Arthur Chu, known to readers of SSC as a person not exactly in favor of niceness, created a Kickstarted project called "Who is Arthur Chu?". Failed by collecting only 20% of the planned $50.000. (Which, if I understand the rules of Kickstarter correctly, means he will get nothing.)
Not sure if the proper reaction here is to laugh (something like: "you had a choice between niceness and winning, you rejected niceness, and no...
It appears to me that all kinds of things are believed among people highly invested in one side or other
True for many political debates in general. Both sides start with different sets of "facts". In worse case, some of those "facts" are factually wrong. In better case, those facts are true, but were selected from the set of all possible facts to support a specific conclusion.
Thus a rational debate would have to start by establishing a base of mutually accepted facts. If you skip this step and go ahead, it will catch you later at some moment.
(For example, we might agree that Jonathan McIntosh is involved in Feminist Frequency, and that his name is usually not mentioned; someone who does not do a background research might easily come to a conclusion that Anita Sarkeesian is doing this alone. -- Of course whether this is a trivial technical detail or a damning evidence, that depends on many other assumptions.)
I'm having trouble figuring out what you think is actually going on here.
I think (p = 0.9) that McIntosh and Sarkeesian are following the "Guide To Exploiting Social Justice People". I think (p = 0.6) that Chu is not aware of this, and that h...
Stuart Russell interviewed by Quanta Magazine on the topic of AI safety.
They touch on the phrase "provably aligned" (with human values), which has been singled out before.
My attempt to delve into Chinese philosophy has brought me to Xunzi. Only the last sentence is short enough to be a quote on its own, but I feel it is strengthened by the paragraph leading to it so much that I have to quote the whole paragraph (which I've separated into multiple paragraphs for readability):
...I once spent the whole day pondering, but it was not as good as a moment's worth of learning.
I once stood on my toes to look far away, but it was not as good as the broad view from a high place.
If you climb to a high place and wave, you have not leng
Alcor 2015 Conference October 9-11, 2015 The Alcor 2015 Conference will be held on October 9-11, 2015 at the Scottsdale Resort and Conference Center at McCormick Ranch, located at 7700 East McCormick Parkway, Scottsdale, AZ 85258.
STAY TUNED FOR MORE DETAILS
Story-like Object: FAQ on LoadBear's Instrument of Precommitment
My shoulder's doing better, so I'm getting back into 'write /something/ every day' by experimenting with a potential story-like object at https://docs.google.com/document/d/1nRSRWbAqtC48rPv5NG6kzggL3HXSJ1O93jFn3fgu0Rs/edit . It's extremely bare-bones so far, since I'm making up the worldbuilding as I go, and I just started writing an hour ago.
I welcome all questions that I can add to it, either here or there.
It seems to me that a lot of "smart" people are capable of applying their intelligence in some spheres, but not others.
...Is this too obvious to be worth mentioning? I say it is not too obvious, for many bloggers have said of Overcoming Bias: "It is impossible, no one can completely eliminate bias." I don't care if the one is a professional economist, it is clear that they have not yet grokked the Quantitative Way as it applies to everyday life and matters like personal self-improvement. That which I cannot eliminate may be well wort
Torture vs. dust specks: I go for dust specks, because it is a reverse lottery. People derive a lot of utility about fantasizing about winning the lottery. Conversely, the disutility of the average person derived from fearing the next time they may be the person tortured is larger than the dust speck. That and sympathetic pain.
Of course it was not in the original definition that people actually know about it. But from my angle every even remotely plausible real life scenario involves that people generally know about it.
Also, social contract theory and slip...
Can we finance cryogenics by revival awards?
Create a market for frozen humans. The reward is for the agent who performs the revival. Investors can either search for revival technology and patent it, or they can invest in frozen humans, which they can sell to agents who wish to attempt revival.
Create a market for frozen humans
That sounds like an excellent plot for a dystopian horror movie.
Can I add an image to the file database, and/or add an image to a post I plan to make in Discussion? The sandbox doesn't explain how to do it, although I did manage to add (well, preview) an already-existing image called Example.jpg.
GiveWell partners with co-founder of Instagram and his fiancée.
http://blog.givewell.org/2015/04/23/co-funding-partnership-with-kaitlyn-trigger-and-mike-krieger/
...We are excited to announce a new co-funding partnership with Kaitlyn Trigger and her fiancé Mike Krieger (co-founder of Instagram)...supporting the Open Philanthropy Project’s work...
...Kaitlyn and Mike have made a financial commitment of $750,000 over the next two years...
...We have reserved a desk in the office for Kaitlyn, and she expects to spend around two days a week there. While she also w
Random policy thought I just had: Hire retired whores to teach sex ed classes. There are no better experts, and they'll (hopefully) be more inclined to teach what people actually want and need to know, rather than transparently disguising scare-em-straight tactics as education.
[Edit: I'm not entirely sure why this got downvoted as heavily as it did; it's the sort of pulling-policy-ropes-sideways thing that I would have expected to go over better here than most places. I'll retract it, but I'll wait a few days first in case someone cares to enlighten me.]
Since you seem to be sincere in asking for reasons:
"Whore" is considered an unpleasant word by many people. That combined with the overall tone may have made people think your intention was trollish
You seem to deeply misunderstand the dynamics that lead to ssex eduation being the way it is. There is no plausible transition from the way the world exists at present to one where retired sex workers were employed in the school system to teach sex education.
a) Because the majority still have moral objections to sex work and it is illegal in many places.
b) there is no common agreement that children should be taught about sex full stop, much less about sexual techniques aimed at pleasure. The only way the very minimal sex education that does exist has been allowed has come to exist is because it framed in terms of health
So, you fixed what you wrote so that it was no longer wrong in the way I described. That's good, but now it looks like I'm an idiot who can't read. (I guess that's why the grandparent of this comment got a downvote.)
If you happen to care about not making people who help you look like idiots (which of course you're in no way obliged to), then in future you might consider acknowledging such corrections rather than silently fixing up what you wrote and then saying "No".
(And since I care -- perhaps foolishly -- about not looking like an idiot, I suppose in future I will have to go to the extra effort of quoting what I'm commenting on more explicitly so as not to be vulnerable to this kind of thing.)
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.