Stuff

I thought I should update the blog even though these days I don’t do a lot of blogging-worthy stuff.

i. A blog I recently discovered: Empirical Zeal. There’s some interesting posts there, for example I liked this one on the state of Indian rural education (though the findings reported are not exactly worthy of celebration).

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ii. The acquisition of language by children. From the introduction:

“Imagine that you are faced with the following challenge. You must discover the internal structure of a system that contains tens of thousands of units, all generated from a small set of materials. These units, in turn, can be assembled into an infinite number of combinations. Although only a subset of those combinations is correct, the subset itself is for all practical purposes infinite. Somehow you must converge on the structure of this system to use it to communicate. And you are a very young child.

This system is human language. The units are words, the materials are the small set of sounds from which they are constructed, and the combinations are the sentences into which they can be assembled. Given the complexity of this system, it seems improbable that mere children could discover its underlying structure and use it to communicate. Yet most do so with eagerness and ease, all within the first few years of life.”

It’s actually pretty wild, once you start thinking about it.

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iii. The Null Ritual – What You Always Wanted to Know About Significance Testing but Were Afraid to Ask (via Gwern? I no longer remember how I found this.). An excerpt from the article:

“Question 1: What Does a Significant Result Mean?

What a simple question! Who would not know the answer? After all, psychology students spend months sitting through statistics courses, learning about null hypothesis tests (significance tests) and their featured product, the p-value. Just to be sure, consider the following problem (Haller & Krauss, 2002; Oakes, 1986):

Suppose you have a treatment that you suspect may alter performance on a certain task. You compare the means of your control and experimental groups (say, 20 subjects in each sample). Furthermore, suppose you use a simple independent means t-test and your result is signifi cant (t = 2.7, df = 18, p = .01). Please mark each of the statements below as “true” or “false.” False means that the statement does not follow logically from the above premises. Also note that several or none of the statements may be correct.

(1) You have absolutely disproved the null hypothesis (i.e., there is no difference between the population means). ® True False ®
(2) You have found the probability of the null hypothesis being true. ® True False ®
(3) You have absolutely proved your experimental hypothesis (that there is a difference between the population means). ® True False ®
(4) You can deduce the probability of the experimental hypothesis being true. ® True False ®
(5) You know, if you decide to reject the null hypothesis, the probability that you are making the wrong decision. ® True False ®
(6) You have a reliable experimental finding in the sense that if, hypothetically, the experiment were repeated a great number of
times, you would obtain a significant result on 99% of occasions. ® True False ®

Which statements are true? If you want to avoid the I-knew-it-all-along feeling, please answer the six questions yourself before continuing to read. When you are done, consider what a p-value actually is: A p-value is the probability of the observed data (or of more extreme data points), given that the null hypothesis H0 is true, defined in symbols as p(D |H0).Th is defi nition can be rephrased in a more technical form by introducing the statistical model underlying the analysis (Gigerenzer et al., 1989, chap. 3). Let us now see which of the six answers are correct:

Statements 1 and 3: Statement 1 is easily detected as being false. A significance test can never disprove the null hypothesis. Significance tests provide probabilities, not definite proofs. For the same reason, Statement 3, which implies that a significant result could prove the experimental hypothesis, is false. Statements 1 and 3 are instances of the illusion of certainty (Gigerenzer, 2002).

Statements 2 and 4: Recall that a p-value is a probability of data, not of a hypothesis. Despite wishful thinking, p(D |H0) is not the same as p(H0 |D), and a significance test does not and cannot provide a probability for a hypothesis. One cannot conclude from a p-value that a hypothesis has a probability of 1 (Statements 1 and 3) or that it has any other probability (Statements 2 and 4). Therefore, Statements 2 and 4 are false. The statistical toolbox, of course, contains tools that allow estimating probabilities of hypotheses, such as Bayesian statistics (see below). However, null hypothesis testing does not.

Statement 5: The “probability that you are making the wrong decision” is again a probability of a hypothesis. This is because if one rejects the null hypothesis, the only possibility of making a wrong decision is if the null hypothesis is true. In other words, a closer look at Statement 5 reveals that it is about the probability that you will make the wrong decision, that is, that H0 is true. Thus, it makes essentially the same claim as Statement 2 does, and both are incorrect.

Statement 6: Statement 6 amounts to the replication fallacy. Recall that a p-value is the probability of the observed data (or of more extreme data points), given that the null hypothesis is true. Statement 6, however, is about the probability of “significant” data per se, not about the probability of data if the null hypothesis were true. The error in Statement 6 is that p = 1% is taken to imply that such significant data would reappear in 99% of the repetitions. Statement 6 could be made only if one knew that the null hypothesis was true. In formal terms, p(D |H0) is confused with 1 – p(D). The replication fallacy is shared by many, including the editors of top journals. [...] To sum up, all six statements are incorrect. Note that all six err in the same direction of wishful thinking: They overestimate what one can conclude from a p-value. [...]

We posed the question with the six multiple-choice answers to 44 students of psychology, 39 lecturers and professors of psychology, and 30 statistics teachers [...] How many students and teachers noticed that all of the statements were wrong? As Figure 1 shows, none of the students did. [...] Ninety percent of the professors and lecturers also had illusions, a proportion almost as high as among their students. Most surprisingly, 80% of the statistics teachers shared illusions with their students.”

The article has much more.

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iv. Diabetes in older Adults.

“More than 25% of the U.S. population aged [>65] years has diabetes (1), and the aging of the overall population is a significant driver of the diabetes epidemic. [...] The incidence of diabetes increases with age until about age 65 years, after which both incidence and prevalence seem to level off”. I should have known the first number was in that neighbourhood, but somehow I had failed to realize that it was that high; most often prevalence estimates are calculated/reported using the entire population in the denominator, but of course such estimates can be deceiving if you do not think about how they are calculated and I clearly hadn’t. At least 1 in 4 in the above-65 age bracket. That’s a lot of people. The article doesn’t have a lot of data, it’s a ‘consensus report’ handling mostly various treatment guideline suggestions and similar stuff.

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v. What is the most uncomfortable situation have you ever been put in- by a guy? Any kind of unwanted flirtation- or something of that nature (Reddit). Lots of really horrible stuff; reading stuff like this makes what might be perceived of as some females’ ‘somewhat overcautious’ behaviour towards members of the opposite sex easier to understand. An example from the link:

“The last stranger-danger moment I will share tonight was at an end-of-midterms party sponsored by the student union at a local bar. I was there with my best friend, and she’s very pretty and very friendly, so we’d very quickly attracted a group of four or five men who were hanging around with us for most of the night. I hadn’t seen any of them before, so I assumed they were students from a different department, and we end up getting a table together and talking for a while. Once my friend mentions that she has a boyfriend, most of them shift their attention to me, though there’s one who still seems interested in her. As I’m talking to them, I find that they’re not students at our university, but that they’re a group of friends visiting from the a couple towns over. Nothing too creepy, so far.

My friend finishes her drink, so the guy she’s talking to goes to buy her another. She’s a little suspicious, so she starts drinking it VERY slowly. Meanwhile, I’m getting distracted talking to one of the guys who works in the same field I’ll be entering soon, and we end up talking for a while about that. He keeps telling me that I’m very beautiful, which I keep brushing off because I knew he was interested in my friend initially, and I was interested in someone else at the time, anyway. Somewhere in the middle of all this, my friend has stopped drinking the drink that was bought for her, and someone asks if she’s going to finish it. She says no.

Eventually, the guy I’m talking to apologizes for his “bad” English, saying that he hasn’t really had to use it since he was in school, which was OVER TEN YEARS AGO. At about the same time, my friend is telling the guy she’s talking to that it’s funny that they decided to visit our city on that particular weekend, because this is a student end-of-midterm party, and he answers, “I know. That’s kind of why we came here.” Someone else asks my friend if she’s going to finish her drink, and she says no, but he can have it if he wants. The drink ‘accidentally’ gets spilled in the process, and she’s signalling me to get the fuck out of there, so I take the opportunity to drag her to the bathroom. I start to notice that she’s acting really fucked up – she can usually drink a ton more than I can, and she’d only had one drink of her own and maybe a third (probably less than that, actually) of the one that guy bought for her. She says she thinks the drink they gave her was drugged, and then she gets sick. I ended up staying the night at her place to keep an eye on her, but I didn’t think to take her to the hospital or anything, so I guess we’ll never know what exactly happened…”

Of course if you’re like me you don’t engage in risky behaviours like drinking with strangers and in that case it doesn’t really matter much if you’re male or female, but then again I’m not like normal people. Most males probably significantly underestimate how risky some of their behaviours – behaviours they would not ever even think of as ‘particularly risky’ – are when a female engages in them. Note that even males that fall into the “I can’t imagine you raising your voice”-category (a female friend said this about me in a conversation I had with her earlier today) are likely to be affected by the behaviours of the (type of) males described in the link; once a female has been through situations like the ones described at the link, she’s less likely to give males the benefit of the doubt and more likely to misinterpret behaviour and the motivations driving behaviour. Reading this stuff has made me believe that the behaviour of ‘overcautious’ females may be better justified and less ‘irrational’ than males tend to think it is.

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vi. I haven’t commented on the new DSM-5 – let’s just say I’ve had better things to do. Here’s one take on it (“It’s arcane, contradictory and talks about invisible entities which no-one can really prove. Yes folks, the new psychiatric bible has been finalised.”). The most ‘relevant’ change to me is the fact that they’ll remove the Asperger Syndrome diagnosis, and instead merge it with other autism spectrum disorders. If you’re asking me what I think about that, the answer is that I don’t really care.

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vii. Cheetahs on the Edge (via Ed Yong). A must-see:

“Using a Phantom camera filming at 1200 frames per second while zooming beside a sprinting cheetah, the team captured every nuance of the cat’s movement as it reached top speeds of 60+ miles per hour.

The extraordinary footage that follows is a compilation of multiple runs by five cheetahs during three days of filming.”

A new blog of interest

I found it via Gwern and it has lots of quotable stuff – some examples from the site:

i. “I awake in bed. I’m warm and safe, like every morning. Outside it is twenty below zero, but from inside my home winter seems far away.

As I rise and stretch, I notice I’m sore. Not from tending the fields though. I have no fields. Some unseen person does all the field-tending for me. Sometimes I forget that there’s any field-tending going on at all.

I buy all my food — I wouldn’t know how to grow it or hunt it. Three or four hours’ pay gets me a week’s worth. It’s a pretty good arrangement. [...]

My soreness is actually from my leisure time, not work. I spent yesterday sliding down a snow-covered slope with a board attached to my feet. After that I was pretty worn out, so I went to a friend’s house, drank beer that was wheeled in from Mexico by another person I never met, and watched a sporting event as it unfolded in Philadelphia.

I don’t live in Philadelphia, but my friend has a machine that lets us see what’s happening there. I have one too. Almost everyone does.

The sun won’t rise for another hour, but I don’t need to light a fire or candles. I have artificial ones, mounted on the ceiling. Hit a tiny switch and I can see everything, any time of day.

I bathe while standing. The water comes out whatever temperature I like.” (from the post A Day in the Future)

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ii. “The body is wonderful. It moves you around, keeps you sharp, manipulates the world for you. It does your job. It gives affection to your loved ones. It carries your life for you. We tend to notice its generosity only once it begins to withdraw it.

It’s also forgiving, maybe a little too much. It will take a lot of shit before it gets mad. [...]

It’s easy to put the body last, because it’s so forgiving and dependable. Normally, it feels like the mind is the boss. But the mind really takes orders from the body. When the body gets run down, thoughts drift into self-defense mode: resentment, victim mentality, self-absorption. The body is suppressing your higher mental qualities, to turn your attention to what is urgent.

The mind then loses its insight and wisdom, and starts grasping at creature comforts. A lot of these — more coffee, another movie on Netflix, a cigarette, a beer, a donut — don’t do the body any favors. So it ramps up the pressure until it has your attention and can deliver its unmistakable message: you are preventing me from doing my job.

The body is the absolute bottom of Maslow’s pyramid. If you don’t take care of it, it will undermine everything until you address the crisis. You won’t be able to focus on your work, you won’t be very sensitive in your relationships, dreams go on hold, and self-confidence shrinks accordingly. [...]

Whoever you are, your body is doing a lot for you, and if you don’t pay its dues, you will be notified.” (from The body is in charge, and won’t let you forget it for long. As a diabetic this was not new stuff – it might be, to some extent, for some of you guys – and in fact it’s stuff I try to always have in mind. In a way I have to always have it in mind – if a type 1 diabetic is not in control of his disease, the disease will control him. That’s just the way it works.)

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iii. “There are others. More than you can comprehend. They’re everywhere you go and you’ll meet some of them.

Some of these other people will naturally establish themselves as an apparent fixture in your life, and change how life looks to you. This is called a relationship. If the person stays around for months or years, your relationship with them might begin to feel permanent.

It’s not. Relationships are conditions, not things. They all have to end at some point. But they will leave something behind for you to keep.

There are different kinds, different styles of rapport between you and The Other: polite, uneasy, romantic, platonic, confusing. We tend to slot them into distinct types — friendships, courtships, marriages, business partnerships — but they’re all fundamentally the same thing. Two people overlap, experience each other’s thoughts and ideas, absorb each other’s values, and learn from each other’s stories. Personalities leak into other people when those people get close enough.

This happens all the time, and it is always temporary. The overlap comes to an end and the parties diverge and drift away. It could be after 72 hours of traveling together, or after a summer internship working together, or after 55 years of marriage. If nothing else ends it, death will.

This means that life is essentially a solo trip. You’ll have this endless parade of visitors, though, which is nice. Characters you couldn’t have imagined will appear, stay for a minute or maybe a few months or maybe many years, and then leave you to your trip. [...]

Most people will enter and exit your life without your noticing much. Some of them will make a big splash though. Some visitors will be decidedly special. You’ll know.

The most valuable experience a person can have is an overlap with this kind of person. The defining characteristic of one of these people is that they make it impossible for you to remain the same person by the time they make their exit. [...]

At any given moment, any time, any day of your existence, you can look at your whole life as a vast collection of experiences, and recognize that all of it adds up exactly to who you’ve become today. Who you became depended — to a degree you may never appreciate — on who you happened to run into while you were out in the world doing your thing. You could have been so many different people.” (from What others leave for you to keep. For what it’s worth, I don’t really agree with the author that relationships always leave you “better than you were” – that idea I consider to just be ‘current me”s attempt to convince current me that current me is a better me than all other ‘potential me’s that could have existed at this precise moment in time. If you want ‘future you’ to be a ‘better you’ than current you, I’m not sure such an approach as the one the author implicitly argues in favour of is all that useful. The approach might trick current you into thinking/feeling that current you is better than past you were, but current you is often a liar who just tells current you what current you would like to hear.)

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iv. “I had life backwards. I figured who I am determined what I was going to do, what I could do. Because of who I was, I couldn’t do X, so I always had to do Y. That’s who I was. Turns out that what I do can change at any time, and that has a direct effect in changing who I am. I never danced because I was never a “person who danced.” Now it’s obvious to me that as soon as I dance in spite of the person I think I am, I quickly become someone who dances. That’s how people who dance become people who dance. They dance.

In other words, it’s behavior that makes the personality, not the personality that makes the behavior, and that revelation is priceless to me.

This means the personality is extraordinarily malleable as long as you don’t forget than not only can you do what’s out of character, doing what’s out-of-character is the only way to grow.

Still, all of us gravitate towards that which is comfortable, which is tantamount to gravitating towards that which does not help you grow.

Anyway, things are blown wide open for me now. Long-neglected goals look fresh again. They’re going to happen. My personality can’t limit me any more, because I’m going to ignore it. I will do what’s out of character, I will surprise those who know me best. I will surprise myself.” (It’s not who you are, it’s what you do)

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If you liked the quotes, you’ll probably like the blog.

A reminder

I mostly post this because people rarely click the links in my sidebar (blogroll etc.) and I think some of you may be missing out on good stuff. So I decided to post a few quotes from more or less random posts at Katja Grace’ blog here, to give you a sense of why I’ve put a link to her blog on my blogroll. Some of her ideas I consider plain weird, but there’s a lot of good stuff too:

i. “people are uncomfortable comparing their friends and partners with others they might have had instead, and in the absence of comparison most people think those they love are pretty good. You rarely hear ‘there are likely about half a billion wives I would like more than you out there, but you are the one I’m arbitrarily in love with’.

This all makes evolutionary sense; blind loyalty is better than ongoing evaluation from an ally, at least towards you. So you evaluate people accurately for a bit, then commit to the good ones. Notice that here the motivation for not comparing appears to come from the benefits of committing to people without regret, rather than the difficulty of figuring out what a nice bottom is worth next to a good career.” (from Experiences are friends)

ii. “When we don’t have concepts for things, we can hardly think about them. When I learn new concepts, I often notice them applying everywhere where before I didn’t even notice anything missing. [...] We don’t invent our own concepts very much; we mostly inherit them from our society. How many concepts that you have did you invent? If it is very few, this is probably not just because society has already found all the useful concepts and given them to you. If you lived a thousand years ago, my guess is that society wouldn’t have given you concepts like ‘subjective probability’ or ‘tragedy of the commons’ or ‘computation’. And no matter how nerdy you are, you probably wouldn’t have made them up. After all, a whole bunch of people did live then, and they didn’t make them up. [...]

Hypothesis: We have relatively few concepts for the world inside our heads, because it’s not very shared, and we get concepts mostly from other people. This means it is hard to think about the world inside our heads, and so also hard to remember. (This is all relative to the world outside our heads, and relative to how we would be if we could show one another inside our heads more).” (from Are we infantile introspectors)

iii. “Why are aphorisms cynical more often than books are for instance?

A good single sentence saying can’t require background evidencing or further explanation. It must be instantly recognizable as true. It also needs to be news to the listener. Most single sentences that people can immediately verify as true they already believe. What’s left? One big answer is things that people don’t believe or think about much for lack of wanting to, despite evidence. Drawing attention to these is called cynicism.” (from Why do aphorisms and cynicism go together?)

iv. “Imagine you were aiming to appear to care about something or somebody else. One way you could do it is to work out exactly what would help them and do that. What could possibly look like you care about them more? The first problem here is that onlookers might not know what is really helpful, especially if you had to do any work to figure it out. So they won’t recognize your actions as being it. You would do better to do something that most people believe would be helpful than something that you know would.

Another problem arises if everyone knows the thing is helpful to others, but they also know that you could do the same thing to help yourself. From their perspective, you are probably helping yourself. Here you can solve both problems at once by just doing something that credibly doesn’t help you. People will assume there is some purpose, and if it’s not self serving it’s probably for someone else. You can demonstrate care better with actions which are obviously useless to you and plausibly useful to someone else than actions plausibly useful to you and obviously useful to someone else. Fasting to raise awareness for the hungry looks more sincere than eating to raise money for the hungry.” (from Being useless to express care)

v. “One way to be more satisfied with life is to lower your standards. People seem pretty hesitant to do this most of the time. And fair enough: who wants to be satisfied at the expense of everything else they care about? Happiness isn’t that great.

If only it were possible to feel like you had lower standards without actually settling for the very easiest career that would pay for your tent, noodles, and blow up companion.

I wonder if this is a significant reason people drink alcohol.

It seems that when people drink they lower their standards for many things. For what to laugh at, for what’s worth saying, and for who it’s worth saying to, for instance. They enthusiastically eat things they would find barely passable sober, and are thrilled by activities they usually find beneath them.

Yet this standard lowering is constrained in time, so as long as you don’t become permanently intoxicated you can spend most of your days having high standards. And since there was a specific identifiable reason for your low standards (even if purely social), it need not contaminate your image as a discerning person. At least not as much.

Is this an actual common point of drinking, or just a side effect? I don’t know – I don’t drink enough, and apparently this isn’t considered a good topic of party conversation.” (from Drinking to lower standards?)

 

A gem

I just found it earlier today. So do I link here, here or perhaps here? I don’t know yet, there’s much to explore and I haven’t spent a lot of time there yet. A longish quote from one of the ‘notes’ (which has more..):

““That is, from January 1926 through December 2002, when holding periods were 19 years or longer, the cumulative real return on stocks was never negative…”

How does one engage in extremely long investments? On a time-scale of centuries, investment is a difficult task, especially if one seeks to avoid erosion of returns by the costs of active management.

‘Unit Investment Trust (UIT) is a US investment company offering a fixed (unmanaged) portfolio of securities having a definite life.’

‘A closed-end fund is a collective investment scheme with a limited number of shares’

In long-term investments, one must become concerned about biases in the data used to make decisions. Many of these biases fall under the general rubric of “observer biases” – the canonical example being that stocks look like excellent investments if you only consider America’s stock market, where returns over long periods have been quite good. For example, if you had invested by tracking the major indices any time period from January 1926 through December 2002 and had held onto your investment for at least 19 years, you were guaranteed a positive real return. Of course, the specification of place (America) and time period (before the Depression and after the Internet bubble) should alert us that this guarantee may not hold elsewhere. Had a long-term investor in the middle of the 19th century decided to invest in a large up-and-coming country with a booming economy and strong military (much like the United States has been for much of the 20th century), they would have reaped excellent returns. That is, until the hyperinflation of the Wiemar Republic. Should their returns have survived the inflation and imposition of a new currency, then the destruction of the 3rd Reich would surely have rendered their shares and Reichmarks worthless. Similarly for another up-and-coming nation – Japan. Mention of Russia need not even be made.

Clearly, diversifying among companies in a sector, or even sectors in a national economy is not enough. Disaster can strike an entire nation. Rosy returns for stocks quietly ignore those bloody years in which exchanges plunged thousands of percent in real terms, and whose records burned in the flames of war. Over a timespan of a century, it is impossible to know whether such destruction will be visited on a given country or even whether it will still exist as a unit. How could Germany, the preeminent power on the Continent, with a burgeoning navy rivaling Britain’s, with the famous Prussian military and Junkers, with an effective industrial economy still famed for the quality of its mechanisms, and with a large homogeneous population of hardy people possibly fall so low as to be utterly conquered? And by the United States and others, for that matter? How could Japan, with its fanatical warriors and equally fanatical populace, its massive fleet and some of the best airplanes in the world – a combination that had humbled Russia, that had occupied Korea for nigh on 40 years, which easily set up puppet governments in Manchuria and China when and where it pleased – how could it have been defeated so wretchedly as to see its population literally decimated and its governance wholly supplanted? How could a god be dethroned?

It is perhaps not too much to say that investors in the United States, who say that the Treasury Bond has never failed to be redeemed and that the United States can never fall, are perhaps overconfident in their assessment. Inflation need not be hyper to cause losses. Greater nations have been destroyed quickly. Who remembers the days when the Dutch fought the English and the French to a standstill and ruled over the shipping lanes? Remember that Nineveh is one with the dust.

In short, our data on returns is biased. This bias indicates that stocks and cash are much more risky than most people think, and that this risk inheres in exogenous shocks to economies – it may seem odd to invest globally, in multiple currencies, just to avoid the rare black swans of total war and hyperinflation. But these risks are catastrophic risks. Even one may be too many.

This risk is more general. Governments can die, and so their bonds and other instruments (such as cash) rendered worthless; how many governments have died or defaulted over the last century? Many. The default assumption must be that the governments with good credit, who are not in that number, may simply have been lucky. And luck runs out.”

Here’s another:

“Why IQ doesn’t matter and how points mislead

One common anti-IQ arguments is that IQ does nothing and may be actively harmful past 120 or 130 or so; the statistical evidence is there to support a loss of correlation with success, and commentators can adduce William Sidis if they don’t themselves know any such ‘slackers’, or the Terman report’s similar findings.

This is a reasonable objection. But it is rarely proffered by people really familiar with IQ, who also rarely respond to it. Why? I believe they have an intuitive understanding that IQ is a percentile ranking, not an absolute measurement.

It is plausible that the 20 points separating 100 and 120 represents far more cognitive power and ability than that separating 120 and 140, or 140 and 160. To move from 100 to 120, one must surpass roughly 20% of the population; to move from 120 to 140 requires surpassing a smaller percentage, and 140–160 smaller yet.

Similarly it should make us wonder how much absolute ability is being measured at the upper ranges when we reflect that, while adult IQs are stable over years, they are unstable in the short-term and test results can vary dramatically even if there is no distorting factors like emotional disturbance or varying caffeine consumption.

Another thought: the kids in your local special ed program mentally closer to chimpanzees, or to Albert Einstein/Terence Tao? Pondering all the things we expect even special ed kids to learn (eg. language), I think those kids are closer to Einstein than monkeys.

And if retarded kids are closer to Einstein that the smartest non-human animal, that indicates human intelligence is very ‘narrow’, and that there is a vast spectrum of stupidity stretching below us all the way down to viruses (which only ‘learn’ through evolution).”

Incidentally, the 20 percent number is somewhat off – if you assume IQ is ~N(100,15), which is pretty standard, then by going from 100 to 120 you will pass by ~40 percent of all individuals, not 20. If you don’t have a good sense of the scale here, it’s a useful rule of thumb to know that ~2/3rds of the observations of a normally distributed variable will be within one standard deviation of the mean. When you jump from 120 to 140, you pass 8,7 percent of all humans, assuming ~N(100,15), a much smaller group of people.

But yeah, as to the rest of it, I have always had some problems with figuring out how to interpret IQ differences, in terms of how differences in IQ translates to differences in ‘human computing power’. And reading the above, it makes perfect sense that I’ve had problems with this, because that’s not easy at all. I wasn’t really thinking about the fact that the variable is at least as much about ordering the humans as it is about measuring the size of the CPU. That’s probably in part because I have an IQ much lower than Gwern.

Bob Glitter er tilbage

Det er et lille stykke tid siden, men jeg opdagede det først nu. Var lidt i tvivl om jeg skulle poste dette indlæg, men nu er det skrevet og så kan man jo lige så godt trykke på publish-knappen. Han er meget grov, men også ret sjov, på sin egen sære måde. Et karakteristisk citat fra denne post:

“Hun tøver ikke med at klassificere sig selv som kunstner, og ethvert forsøg fra læreren på at overlevere praktiske teknikker til at komme videre med skrivningen, afviser hun med det samme. Hvis man skal arbejde, er det ikke rigtig kunst. Det skal helst bare sive fra hendes fantastisk dybe og indsigtsfulde indre og skal ikke være konstrueret på nogen som helst lavpraktisk facon. Derfor laver hun heller ikke noget, når vi har skriveøvelser på kurset. Undtagen når der skal skrives digte, åbenbart. Og der er hun tilsyneladende også yderst ivrig for at læse op. Jeg vægrer mig ved at citere:

”Mandag morgen er majstænder
og brune gardiner.”

På dette tidspunkt var det ikke blot mine tæer, der krympede sig. Enhver celle i min krop var i gang med at vende vrangen ud på sig selv i synkrondans med min mavesæk. Jeg tror, blodet stoppede med at cirkulere, og jeg kom først til mig selv, da jeg fik tungen i klemme under mine fortænder, der ved hjælp af min kæbes krampen havde boret sig ned i bordpladen foran mig. Desværre var hun ikke helt færdig endnu:

”Te-bolle-chokolademand
med kaffe og kage til.”

Bagefter var der stilhed. En ældre dame overfor mig sad med et skævt, eftertænksomt smil, satte hovedet på skrå og lavede et lille pust med næsen, som om der lige var blevet serveret et lille stykke sushi af klogskab foran hende. Læreren roste. Digtet var tilsyneladende godkendt.”

…

Her er et tidligere indlæg fra bloggen som også er meget karakteristisk. Hvis du ikke kan li’ ovenstående uddrag vil du næppe bryde dig om bloggen. Nogle læsere af denne blog vil sandsynligvis føle sig som nogle af bitterblogs mål, især de relativt venstreorienterede, offentligt ansatte, kvinder, muslimer, homoseksuelle, humanistisk uddannede, handicappede, journalister, overvægtige, folk som går med designerbriller, feminister, folk som drikker fair trade kaffe… (ok, så mange læsere har jeg ikke, men…) og de vil nok have det svært med nogle af hans sure opstød – det er en politisk blog, fyldt med overdrivelser, generaliseringer, stereotyper osv., og han er som sagt ret grov. Bitterblog var i sin tid en af mine ‘guilty pleasures’, ved ikke hvad man kalder det på dansk; den bliver det nok igen nu.

100.000 hits

Jeg burde ikke omtale det. Hit nummer 99.999 er nu engang objektivt set ikke hverken mere eller mindre væsentlig end hit nummer 100.001, og begge hits er faktisk pænt ligegyldige. Men jeg kan ikke lade være.

Tak til de faste og semi-faste læsere for fortsat at få det til at give bare en smule mening at blogge.