Learning to be Terse

A three-way split. If only they’d split it four ways…

Posted in News by Croor Singh on September 30, 2010

Initial reports of the Ayodhya title suit verdict from the Allahabad High Court have been coming in. It seems that the three judges (two hindus, one muslim) agree that the land should be split among the three petitioners, but disagree about the proportions.

At least from what I’ve heard, the 1961 plaint from the Waqf board has been dismissed as having exceeded the statute of limitations (which basically means they didn’t appeal within a certain time limit), but the court has still decided that the land must be split between a shrine for the hindus, a mosque for the muslims and something called the nirmohi akhara.

I have a better option, courtesy Anubhab Roy: split it four ways. The hindus who are so inclined can pray to Ram. The muslims who are so inclined can pray to Allah. The nirmohi akhara can do whatever it is that it does. The fourth split should be land for a strip club. You know, prayer is hard work, and we all know there should be some play after hard work.

Go on, then, Messrs. Justices of the Allahabad High Court, give us a strip club. That would be as good a verdict as anything you might drum up.

2010 September – Month in review

Posted in Weblogs by Croor Singh on September 30, 2010

This has been a fairly hectic month on the blog, and the busiest one yet (I’ve only been writing here for five months, so I don’t know what that ‘yet’ is worth). I thought these posts/comments from September are worth a second read.

Roughly chronologically, then:

1) The Indian armed forces in Kashmir are seen to be taunting Kashmiris, even throwing stones at houses in residential areas, in this video from Facebook. The Union Minister of State for Defence says the army needs the AFSPA to ensure that the human rights of the soldiers are protected. Up is Down. Down is Up.

2) IIT Madras punishes students caught cheating in an exam, which most people here agree is fair; and people caught marking proxy attendance, which people think is a bit harsh. A ‘Dude’ comes along, makes silly comments, and gets skewered.

3) A remarkably stupid ‘study’ conducted by the gits at Ericsson Malaysia claims that women are going to ‘rule the workplace’ by 2020. Why? Because it looks like they might have about a third of the jobs, worldwide.

4) The Prime Minister asks the Supreme Court to mind its own business and not try and make public policy decisions. He also talks about dissent and disagreement in his Cabinet and says this is a good thing, in this interview with several editors.

5) A crazy pastor in Florida wants to burn a copy of the Quran, people all over the world freak out, an attorney in Australia smokes weed made from pages of the Quran, finds that it sickens him, and loses his job. A teacher in Kerala gets his hand chopped off by thugs, and also gets deserted by his employers and his Church. This stupid bitch tries to coach muslim women on how they can avoid having to reveal their faces in public.

6) People here find out about how colleges in Chennai have the most god-awful, batshit crazy rules about male and female students talking to each other in college. Thankfully, the reaction (on this blog) is the sensible ‘WTF are they thinking?!’ There is also this rant about children being treated like racehorses and made to compete, presumably to stroke the egos of the parents.

7) Vir Sanghvi calls for religion to be left a personal and private affair, and points out what he thinks is the fundamental difference between Indian religion and the Abrahamic religions. In a different context, I talk to my professor about something and a delightful verse from the Rig Veda comes up.

8.) I read a very interesting paper about nurse-bees and circadian rhythm modulation and write about it, only to learn that people aren’t really that interested in chronobiology.

9) Several things about probability (see {this}, or {this}, or {this}) were said. The last link there is to a post that had wrong calculations, which commenters were quick to point out. That led to this retraction and a correction, due to Anant LK Kumar. There was, finally, this post about asymmetric dominance.

Conspicuously absent from the above list is any mention of the posts about affirmative action. A summary of those arguments (with Nair, mostly) will be the subject of an separate post one of these days.

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Monthly Tally for September 2010: 54 posts, 3100 blog hits, ~150 comments.

Overall Tally: 189 posts, 9600 blog hits, 442 comments.

[End. Fini. Kaputski.]

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Of bottles of wine and Asymmetric Dominance

Posted in Science by Croor Singh on September 29, 2010

Nair mentioned in the comments here something called ‘asymmetric dominance’. He mentioned this in the context of this talk by Dan Gilbert, the researcher who I pointed out had very interesting things to say about people and how we think about probabilities.

I want to try and explain what asymmetric dominance is. Let’s say that there are two versions of a watch (or car, or unicorn) that are on sale. The inexpensive version has fewer things of luxury, obviously. In this case, a survey of what people buy usually shows that the trend observed is correlated to the spending power. That is, if people are prepared to spend only so much on a watch, and only the inexpensive version fits in their budget, that’s what they’ll buy. If people can afford the expensive version, they buy that.

Let’s say now, that somebody (who simply couldn’t help themselves) introduces a third version of the watch. This version is priced somewhere between the other two versions. Except, on the scale put in place by the other two versions (i.e. difference in worth between the two versions, in comparison with the difference in price), this third version is hugely overpriced – it is only a little better than the inexpensive version, but is a lot more expensive. An explanation of the phenomenon of asymmetric dominance works best if this third version is patently and obviously bad, so let’s assume it is.

One would expect, rationally, that people will still only buy the two original versions. One would also expect, then, that the number (or ratio) of people who buy one version or another shouldn’t change. One would be wrong. It turns out that people, faced with this new third choice which is so obviously bad, choose the (original) expensive version a lot more often than they would have if they only had the two original choices.

‘Intelligent’ supermarkets, then (in addition to putting dairy products and bread and eggs as further back on their aisles as possible), put validly expensive products next to the third kind of obviously bad bargains, apparently.

A seemingly related observation is that people (including professional wine-tasters) who are asked to test a bottle of wine think it tastes better if they are told that it costs more than it actually does. Go figure.

He surely knows… or perhaps He does not!

Posted in Skepticism, Society by Croor Singh on September 28, 2010

There was this talk by Jairam Ramesh, the Union Minister for Environment and Forests, at JNCASR today. I’ll write about the talk and the questions and answers at the end in a day or two; I had a fascinating discussion with Roddam Narasimha, this professor of mine – who knows just about everything – about the talk, and something Jairam Ramesh said came up in the discussion.

Jairam Ramesh quoted Alberuni’s comment about Indians that (this was a thousand years ago, mind; it seems like we haven’t changed one bit), presented with a choice between two things, Indians choose both. The minister used this to point out that the dithering usually involved in saying no to haphazard industrial development even when we know it will cause environmental destruction is symptomatic of this.

RN agrees that this is true, but says that this isn’t always a bad thing. He says, and I agree, that this is perhaps the most fundamental difference between Indian and western philosophy – we are all right with saying ‘maybe this. maybe that. maybe both, or neither’.

Here’s a for-instance: the creation stories of the world are usually full of unseemly certainties – god created man and earth and all the shit within and without starting on a Monday, working through the week, and resting on Sunday. What the Rig Veda (which is the text that deals with creation) says is delightfully skeptical. Amartya Sen quotes this stanza in The Argumentative Indian.

iyam visrstir yata ababhuva;
yadi va dadhe yadi va na:
yo asyadhyaksah parame vioman,
so anga veda, yadi va na veda.
[/end stanza]

That translates (roughly) to: “Where did this universe come from? Did He create it, or did he not? Only he who is the master of all this knows; Or perhaps he doesn’t.”

To be sure, there are other places in the vedas and other texts where the creation story is told in more descriptive – and more ‘certain’ – terms: there was an egg that gave rise to Brahma, who went crazy and pooped all over. Or something. Also, that stanza seems to presume a creator, and that ‘he’ is male, and that ‘he’ is the master; the nice thing about the stanza, though, is that it leaves the options open, and leaves the ‘creator’ a completely impotent being.

I can very easily imagine somebody from that tradition, on being told that Adam was created on Saturday, 30th of September, 4004 BC and that the woman was created from the man’s rib, and that God rested the next day, would do exactly what I would do today – point, and laugh.

[End. Fini. Kaputski.]

Random Photograph – From the EMU Rooftop

Posted in Campus, Photographs by Croor Singh on September 28, 2010

EMU has a nice rooftop to take pictures from (reminder to self: get to and leave camera at lab). I took a few the last time I had my camera here. This one, I thought, was nice. If you zoom in, you can see me on the window of the other building (that’s the Nanoscience building, if you’re curious). That guy on the phone, whose name I don’t know, is also from EMU.

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Cruelty to Animals? We treat children worse.

Posted in Inanity, Society by Croor Singh on September 27, 2010

I know of many people who can blow the roofs off halls with their music. I even know some of this kind personally. A virtual rule with people of this kind seems to be that they started young, which I guess is true of pretty much everything in the creative arts.

That said, here’s something I saw on TV last week that made me shudder. There are these competitions that judge how well people sing. With the number of TV channels growing every day, the number of these is as well. These competitions are also held for children. That’s bad enough, right? I mean, do ten year-olds need to be told they are good, or worse – no good, at singing? To be fair, there are some programmes that do this gently, and try and explain to the kids the mistakes they make as areas for improvement.

And then there are the programmes of the kind that was blaring on the TV in the hall at JVH. This was on Zee Kannada, on a programme called ‘Sa-ri-ga-ma-pa’, if somebody wants to check the next time they air this crock. This programme actually holds eliminations for the kids on it. With all the theatrics of American Idol, except with creepier music. That, and they’re doing this to kids.

” Now let’s find out who stays and who goes home. We have  contestants A, B, C, and E. D is safe from elimination because she won last week’s round. Okay, then…

The first one to progress to the next round is… E! **Boom! [Cue creepy music]**

The next one to get into the next round is B! **More boom! [Cue creepier music] **

We’re now left with A and C! Out of these two, the judges have gone with the beautiful smile of C!    ** You know **

We’re sorry, A, but we have to send somebody home. You have been eliminated. ** [Cue depressing music, this time] ** “

The above, if you are suspicious, isn’t a caricature. This is actually what the fucking git of a host said to the frikkin’ ten year-olds on the show. Including the suspenseful drumroll ending in a flourish and the creepy music… And the ‘we choose the nicer smile‘ bit. What the heck does a smile have to do with a singing contest? Wait, let me rephrase that. How fucking stupid does somebody have to be to do this to a ten year-old?

Now, like I said, this stupidity may not be representative of every singing programme on TV. But this is what happens when there are fifty of these programmes and each of them tries to outdo the others in ‘excitement’. And the only way these nitwits can drum up excitement is to play Russian roulette with kids to decide who gets to play Russian roulette next week.

[End. Fini. Kaputski.]

Tell a story – 2 – With a graph

Posted in GraphJam, People by Croor Singh on September 26, 2010

There are geeks and nerds and there are geeks and nerds. The thing about geeks and nerds is that most of us tend to be socially awkward. Perhaps this will help you understand better: some of us are the Leonard Hofstadter kind of socially awkward – we want to fit in, but don’t know how to. Some of us however, are the Sheldon Cooper kind of socially awkward – we border on the misanthropic.

The thing is, though, that even Sheldon Cooper has a certain bunch of people he is friendly with. Vattam was telling me last night that I tend to be this way. It seems he says, and I agree, that I have a circle of friends with whom I’m positively garrulous, but around everybody else, I go into a shell.

There can be one more dimension to this, it turns out: Sheldon Cooper, as a rule, never has more than four friends; it’s too hard to maintain more than four friendships, he says. The number of people I’m prepared to let my guard down around isn’t that restricted. I’m just nutty about who it is I let into this ‘circle’. Time spent together seems to have nothing to do with this. Neither does gender. Let’s just say there’s a reason even I call this behaviour of mine ‘nutty’.

And now, since the title of this post says ‘graphs’, here’s a graph that says everything I’ve just said:

[graph]

[/graph]

If you’re somebody this graph applies to, where in this plane do you think you are?

[End. Fini. Kaputski.]

Tell a story – 1 – With a cartoon

Posted in Campus by Croor Singh on September 26, 2010

Pretty much the whole group at the engineering mechanics unit at JNC eats together. (You know this, of course, if you read this blog with any regularity!) The walk to the mess is quite leisurely, as is what usually happens when large groups herds of people meander towards the mess watering hole.

There are quite a few characters in the group here at the EMU, and I’m not just talking about myself in the third person.  This is among the more ‘visible’ people at EMU, JNCASR. This is also the first caricature I’ve tried that isn’t of myself. This is what I see on the way to lunch every day.

This, boys and girls, is Anubhab Roy!

[anubhab]

[/anubhab]
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The Probability Mess – I get email

Posted in People, Science, Weblogs by Croor Singh on September 25, 2010

I wrote about some probability calculations that I’d done on a whim. LK (that’s Anant without the ‘h’) says, on email that he thinks my calculations were wrong. He sent me this figure to make his point:

You should be able to check that the probability from that figure is closer to a third than to a sixth. This is proof positive that I was wrong, and that LK’s answer in the comments on the last post was right (although there still is no (120-t) in any denominator).

I am usually willing to be shown wrong, and to accept it when I am. Here, though, I couldn’t stop myself – out of disbelief, mostly – from writing my own test on MatLab, and re-doing the expression for the probability; correctly, this time.

Here, first, is the expression for the probability, in terms of ‘m’, the time I spend in the mess, and ‘n’, the time Avani spends in the mess. The first line simplifies to the second

The MatLab code I wrote is here, so you can check the results for yourself.

I’d averaged the second terms in each bracket as (m/2) and (n/2) respectively, the last time. Obviously, that’s the wrong thing to do. The expression above gives an answer that is close to, but not exactly, what LK got. The MatLab simulations also give similar probabilities. I can’t explain what is causing the discrepancy between the expression and LK’s vastly more understandable graph. Maybe LK will help.

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More Probability – the conditional kind

Posted in Science by Croor Singh on September 24, 2010

Since I’ve been writing about probabilities and their calculation (see {this}, or {this}, or {this}) of late, I thought I’d say something about Bayes’ theorem and conditional probability. Pogo asked me yesterday to do some calculation so he could verify whether he’d done the right thing on some test.

This is a modified version of the problem: there’s a new protocol that claims to detect drunkenness in motorists. The people who’ve devised this protocol claim that the test is 95% accurate. That is, out of 100 drunk people you check, the test will pick out 95; mutatis mutandis for sober people. What do you think? Is 95% accurate enough for a something that is supposed to stop people from driving around drunk? That’s a useless measure of how good the test is, it turns out. For example, I have a test that picks out every drunk person – when asked if somebody is drunk, I say yes.

What somebody who is using this protocol on the ground will want to know is how much they can trust the test when it says somebody is drunk. This is where conditional probability comes in. So, given that the test is 95% accurate, and that out of 100 motorists, 90 are sane (and hence not drunk when they are driving), and that the test says subject A is drunk, with what confidence should the police officer arrest A? The answer, perhaps surprisingly, is only 68%. This is the probability that the fellow your test said was drunk was actually drunk, as opposed to being one of the 5% who weren’t drunk but got pointed to wrongly. That 5% error leads to a 32% false-accusation rate.

How about if the test was 99% accurate? The false-accusation rate is still about 8.33%, unacceptable by rigorous legal standards. To see why that’s unacceptable, check what happens if not 90, but 95% people are sober, and the test is only 90% accurate, and not 95%. You should check that of the positive tests 68% will be false-positives! And this is with ~5% variation in assumed parameters. Any more and the situation will get worse.

To see where this could be life-altering and not just a nuisance, imagine what would happen with ‘tests’ that are supposed to pick out terrorists. Even a test that claims to be 99.99% accurate, because the number of ‘terrorists’ is such a small fraction of the total population, will pick out far too many people who’re innocent. For a ‘terrorist ratio’ of one in a million, for example, the test (which is 99.99% ‘accurate’, remember) will pick out 99 innocent people for every terrorist.

On a less sombre, but no less interesting, note, here’s xkcd’s take on conditional risk:

[xkcd]
[/xkcd]

Can you tell why the fact that the death rate among people who know some statistic is one in six is irrelevant, though quite funny in context?

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Note: A slightly more involved version of this problem can be constructed by differentiating between false-positives and false-negatives, i.e. the ratios could be different. Pogo’s problem had  8% and 5% respectively, for instance.

Leonard Mlodinow‘s book, The Drunkard’s Walk: How Randomness Rules Our Lives, is an excellent read for people with a wide range of acquaintance with probability theory. The book is available as a paperback. Pogo let me borrow his copy to read.

[End. Fini. Kaputski]

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