It's an old book, I know, and one that many of us have already read. But if you haven't, you should.

If there's anything in the world that deserves to be called a martial art of rationality, this book is the closest approximation yet. Forget rationalist Judo: this is rationalist eye-gouging, rationalist gang warfare, rationalist nuclear deterrence. Techniques that let you win, but you don't want to look in the mirror afterward.

Imagine you and I have been separately parachuted into an unknown mountainous area. We both have maps and radios, and we know our own positions, but don't know each other's positions. The task is to rendezvous. Normally we'd coordinate by radio and pick a suitable meeting point, but this time you got lucky. So lucky in fact that I want to strangle you: upon landing you discovered that your radio is broken. It can transmit but not receive.

Two days of rock-climbing and stream-crossing later, tired and dirty, I arrive at the hill where you've been sitting all this time smugly enjoying your lack of information.

And after we split the prize and cash our checks I learn that you broke the radio on purpose.

There once lived a great man named E.T. Jaynes. He knew that Bayesian inference is the only way to do statistics logically and consistently, standing on the shoulders of misunderstood giants Laplace and Gibbs. On numerous occasions he vanquished traditional "frequentist" statisticians with his superior math, demonstrating to anyone with half a brain how the Bayesian way gives faster and more correct results in each example. The weight of evidence falls so heavily on one side that it makes no sense to argue anymore. The fight is over. Bayes wins. The universe runs on Bayes-structure.

Or at least that's what you believe if you learned this stuff from Overcoming Bias.

Like I was until two days ago, when Cyan hit me over the head with something utterly incomprehensible. I suddenly had to go out and understand this stuff, not just believe it. (The original intention, if I remember it correctly, was to impress you all by pulling a Jaynes.) Now I've come back and intend to provoke a full-on flame war on the topic. Because if we can have thoughtful flame wars about gender but not math, we're a bad community. Bad, bad community.

If you're like me two days ago, you kinda "understand" what Bayesians do: assume a prior probability distribution over hypotheses, use evidence to morph it into a posterior distribution over same, and bless the resulting numbers as your "degrees of belief". But chances are that you have a very vague idea of what frequentists do, apart from deriving half-assed results with their ad hoc tools.

There is a flipside to the trivial inconvenience: the trivial impetus.  This is the objectively inconsequential factor that gets you off your rear and doing something you probably would have left undone.  It doesn't have to be a major, crippling akrasia issue.  I'm not talking so much about finishing your dissertation or remodeling your house, although a trivial impetus could probably get you to make some progress on either.  I'm talking about little things that make your life a little better, like trying a new food or permitting a friend to drag you along to a gathering of people and pizza.

An illustrative anecdote: the first time I tried guacamole, I was out with my family at a restaurant and my parents decided to order some.  The waiter came out with a little cart with decorative little bowls full of ingredients and a couple of avocados, and proceeded to make guacamole right there with all the finesse of one of those chefs at a hibachi restaurant.  He then presented us with the dish of guacamole and a basket of chips.

If my prior reasons for avoiding guacamole had been related to concerns about its freshness or possible arsenic content, this would have been a non-trivial reason to try the new food, but they weren't - I was just twelve, and it was green goop.  But on that day, it was green goop that someone had made right in front of me like performance art!  I simply had to have some!  It was delicious.  I have enjoyed guacamole ever since.  I would almost certainly have taken years longer to try it, if ever I did, had it not been for that restaurant's habit of making each batch of guacamole fresh in front of the customer.

Not all trivial impetuses have to be so random and fortuitous.  Just as you can arrange trivial inconveniences to stand between you and things you should not be doing, you can often arrange trivial impetuses to push you towards things you should be doing.  For instance, I often get my friends to instruct me to do things when I'm having trouble getting moving: sometimes all it takes to get me to stop dithering and start making the pasta salad I agreed to bring to a party is someone agreeing when I say, "I should make pasta salad now".  Or "I should go to bed now", or "I should probably pay that bill now".

Does anyone have any other ideas for trivial impetuses that could be helpful in fighting small-scale akrasia (or large-scale)?

Politics is the mind-killer. A while back, I gave an example: the government's request that Kelloggs  [EDIT: General Mills, thanks CronoDAS] top making false claims about Cheerios. By the time the right-wing and left-wing blogospheres had finished with it, this became everything from part of the deliberate strangulation of the American entrepreneurial spirit by a conspiracy of bureaucrats, to a symbol of the radicalization of the political right into a fringe group obsessed with Communism, to a prelude to Obama's plan to commit genocide against all citizens who disagree with him. All because of Cheerios!

Why? What drives someone to hear about a reasonable change in cereal advertising policy and immediately think of a second Holocaust?

This reminds me of something I used to notice when reading about politics. Sometimes there would be a seemingly good idea to deregulate something that clearly needed deregulation. The idea's proponents would go on TV and say that, hey, this was obviously a good idea. Whoever by the vagary of politics had to oppose the idea would go on TV and talk about industry's plot to emasculate government safeguards. Predatory corporations! Class solidarity! Consumer safety!

Then the next day, there would be seemingly good idea to regulate something that clearly needed regulating. The idea's proponents would go on TV and say that, hey, this was obviously a good idea. Its opponents would go on TV and say that all government regulation was inherently bad. Small government! Freedom! Capitalism!

I have found a pattern: when people consider an idea in isolation, they tend to make good decisions. When they consider an idea a symbol of a vast overarching narrative, they tend to make very bad decisions.

Disclaimer: If you are prone to dismissing women's complaints of gender-related problems as the women being whiny, emotionally unstable girls who see sexism where there is none, this post is unlikely to interest you.

For your convenience, links to followup posts: Roko says; orthonormal says; Eliezer says; Yvain says; Wei_Dai says

As far as I can tell, I am the most active female poster on Less Wrong.  (AnnaSalamon has higher karma than I, but she hasn't commented on anything for two months now.)  There are not many of us.  This is usually immaterial.  Heck, sometimes people don't even notice in spite of my girly username, my self-introduction, and the fact that I'm now apparently the feminism police of Less Wrong.

My life is not about being a girl.  In fact, I'm less preoccupied with feminism and women's special interest issues than most of the women I know, and some of the men.  It's not my pet topic.  I do not focus on feminist philosophy in school.  I took an "Early Modern Women Philosophers" course because I needed the history credit, had room for a suitable class in a semester when one was offered, and heard the teacher was nice, and I was pretty bored.  I wound up doing my midterm paper on Malebranche in that class because we'd covered him to give context to Mary Astell, and he was more interesting than she was.  I didn't vote for Hilary Clinton in the primary.  Given the choice, I have lots of things I'd rather be doing than ferreting out hidden or less-than-hidden sexism on one of my favorite websites.

Unfortunately, nobody else seems to want to do it either, and I'm not content to leave it undone.  I suppose I could abandon the site and leave it even more masculine so the guys could all talk in their own language, unimpeded by stupid chicks being stupidly offended by completely unproblematic things like objectification and just plain jerkitude.  I would almost certainly have vacated the site already if feminism were my pet issue, or if I were more easily offended.  (In general, I'm very hard to offend.  The fact that people here have succeeded in doing so anyway without even, apparently, going out of their way to do it should be a great big red flag that something's up.)  If you're wondering why half of the potential audience of the site seems to be conspicuously not here, this may have something to do with it.

Human beings are all crazy.  And if you tap on our brains just a little, we get so crazy that even other humans notice.  Anosognosics are one of my favorite examples of this; people with right-hemisphere damage whose left arms become paralyzed, and who deny that their left arms are paralyzed, coming up with excuses whenever they're asked why they can't move their arms.

A truly wonderful form of brain damage - it disables your ability to notice or accept the brain damage.  If you're told outright that your arm is paralyzed, you'll deny it.  All the marvelous excuse-generating rationalization faculties of the brain will be mobilized to mask the damage from your own sight.  As Yvain summarized:

After a right-hemisphere stroke, she lost movement in her left arm but continuously denied it. When the doctor asked her to move her arm, and she observed it not moving, she claimed that it wasn't actually her arm, it was her daughter's. Why was her daughter's arm attached to her shoulder? The patient claimed her daughter had been there in the bed with her all week. Why was her wedding ring on her daughter's hand? The patient said her daughter had borrowed it. Where was the patient's arm? The patient "turned her head and searched in a bemused way over her left shoulder".

I find it disturbing that the brain has such a simple macro for absolute denial that it can be invoked as a side effect of paralysis.  That a single whack on the brain can both disable a left-side motor function, and disable our ability to recognize or accept the disability.  Other forms of brain damage also seem to both cause insanity and disallow recognition of that insanity - for example, when people insist that their friends have been replaced by exact duplicates after damage to face-recognizing areas.

And it really makes you wonder...

...what if we all have some form of brain damage in common, so that none of us notice some simple and obvious fact?  As blatant, perhaps, as our left arms being paralyzed?  Every time this fact intrudes into our universe, we come up with some ridiculous excuse to dismiss it - as ridiculous as "It's my daughter's arm" - only there's no sane doctor watching to pursue the argument any further.  (Would we all come up with the same excuse?)

If the "absolute denial macro" is that simple, and invoked that easily...

No, I don't mean that the news media are biased politically.  I mean that authors are biased by the media they use.

I'm learning about support vector machines (SVMs).  There are a lot of books and articles written on SVMs.  There are also a whole lot of video lectures on SVMs at videolectures.net (see "kernel methods").

People go into much greater detail in lectures than in text.  I like to work with text.  I'd like to have a text on SVMs that goes into as much detail as videos on SVMs usually do, and works out the ideas behind the concepts as thoroughly, but no such text exists.  For some reason, giving a 5-hour lecture series in which you describe the motivations, applications, and work out the mathematical details is acceptable; but writing a text of the same level of detail, which might take only 2 hours to read, is not.

Perhaps this is because writers are motivated to keep pagecounts low.  But pagecount no longer matters with electronic articles.  Yet writers still don't want to explain things thoroughly.  They certainly aren't saving their readers any time by leaving out intermediate steps.  A longer article would take less time to read (and possibly less time to write).  Another problem with the pagecount theory is that texts routinely include footnotes and appendices, contributing to the pagecount; yet relegate them to the back of the book, as if embarassed of them, despite the fact that this makes them very difficult to use.

It's especially bad in math, in which writers have a long tradition of deliberately concealing difficult steps and leaving them "as an exercise to the reader".  For some reason it is considered bad form to write out all of the steps in a proof, even if adding one or two lines could save the reader five minutes of puzzling.  I read an electronic article yesterday where the author said, "These two equations are actually equivalent.  Do you see why?"

I think people have adopted a set of cultural biases about what is appropriate in lectures vs. in writing by simply counting observations, without thinking about the systematic sample bias.  Speakers speak the way they've seen other speakers speak, without recollecting that most of those speakers were instructors.  Technical writers, meanwhile, are picking up their cues from authors of textbooks, which are written with the assumption that a person will be on hand to take you through the details; and applying them in situations where no such person will be available.