Posts Tagged ‘Statistics’

Dec
30
2005

The Accidental Utility of Slashdot

I've been reading Slashdot for the last year and a half or so. I stayed away from it until I downloaded an aggregator that had it preinstalled, and, well, it just kind of stayed there. I don't post comments myself, but I find find those who do interesting. Of course, it's probably not for the reasons they had intended.

I think Slashdot is a great way to measure my own susceptibility to argumentum ad verecundiam. I do this (retrospectively) by reflecting on to what degree I have agreed with the posts scoring "5, Informative" or "5, Insightful" when attached to topics I know relatively little about. I contrast that with how ignorant posts with the same rating seem when in reply to topics I know inside and out.

What is more likely? That only the high-scoring commentators on "my" topics make serious errors? Or that the overall intelligence and ability of the commentators is fairly uniform, and I attribute too much credit to them when I don't know the material? Meeting one or two posters in real life might bias your response, but I digress.

In Humans First Arose in Asia, for example, some of the comments currently scored as fives give away obvious misconceptions of the time frame of human evolution. There are good comments too, but the scoring system does a poor job of differentiating them. Competitors like Digg and Reddit suffer from similar problems with varying degrees of severity. (I can't read Digg at all, and I'm currently giving Reddit a "time-out" after it linked to one too many pseudoscientific/conspiracy-theory articles.)

So what's the point here? Just that adequate English skills combined with an argument that sounds logical can easily be mistaken for an argument that is correct.

Tags: , , ,
Posted in Eccentric | No Comments »

Dec
29
2005

I’m All Sixes and Sevens and Nines

The following is a review of A Mathematician Plays the Stock Market, by John Allen Paulos.

One of my inaugural tasks at my current job was developing a technical analysis package for market data. I have to admit I rather enjoyed this, for a few reasons only tangentially related to the specific technology at hand.

First, I like solving math problems–always have. Writing programs that do this for me are more enjoyable still. Second, there was the shameful thrill of scrawling some equations involving capital sigmas (the kind of thing those of us destined to be computer scientists are doing by eighth grade) on a whiteboard and watching the panicked expressions of the business and finance people present.

I guiltily concede that the latter motivation was the dominant one. I still keep a sheet with sigmas painted all over it within reach. Anytime I’m asked about the output of my analysis package, I produce it from deep within my desk which by the way, overwhelmingly contains only ketchup (Heinz) and straws (plastic, non-bending). I’ll scribble some new symbols on it and say something like, “so as you can see, the limit of this term as phi approaches infinity is…” and before I’ve finished the sentence the person has muttered something in bewilderment and shuffled away.

dice

I’m not necessarily doing this out of malice or contempt, it’s just that I realized a long time ago that the technical analysis of market data is largely a crock. I’ve always carried this nagging little fact with me, and at times I’ve pondered the morality of having this job at all. So I’m not really doing the user a disservice here, unless I’m somehow expected to explain to everyone in the world that you can find meaningful patterns in any set of data–words in the bible, petals on a flower, sand on the beach, or the price of Superconductor (NasdaqSC:SCON). Chances are, the pattern that you discover holds no predictive power.

So it’s really not important to the person asking what the answer is, it’s just reassuring to believe that I possess one. In the end, they will probably make about as much money as chance would dictate. Maybe a little more, maybe a little less. If they do happen upon the holy grail, that ineffable oracle of a model that really can forecast the future, it is as likely to be in spite of my explanation as it is to be caused by it. Populus vult decipi; decipiatur.

How odd it is, I found myself thinking while reading this book, that there exists a Nobel prize for Economics yet none for Mathematics. Is my support for this book just another example of confirmation bias? I’m obviously not qualified to say. I suggest you judge it for yourself.

Tags: , , ,
Posted in Eccentric | No Comments »

Dec
03
2005

A Plea for Change in Sports Commentary

Here is one football statistic that I never want to hear again:

Team X is 40-0 when they have someone rush for 100 yards.

The conclusion you are supposed to draw is that Team X should try to run the football. Here's one way you could rephrase the statistic:

Team X does a pretty good job of winning when they're winning.

It's post hoc reasoning, people! Come on! I'm starting to think Howard Cosell was on to something when he spent years hating on Frank Gifford because he was not a trained sports journalist. I don't have a high opinion of journalists either, but now the Giffords are the norm in the commentary business. The intelligence of the analysis suffers. I'm all for coaches-as-commentators, but I think we should all agree that players-as-commentators is not working out.

Tags: , , ,
Posted in Sports | No Comments »

Jul
16
2005

A Macroeconomic Theory of Texas Holdem

I am having a banner day as an intellectual, it being no coincidence that my television is currently broken. I could take this excellent opportunity for creative output to bemoan yet another unfathomably stupid government-funded “power of prayer” study, but I opted for a more lighthearted subject.

To be completely candid, I started doing just that, but I depressed myself too much to finish it.

Therefore, I will regale you, the reader, with a dissertation on another utterly important subject. Namely, gambling.

Trading emails with a friend the other day, I described the poker craze that is gripping the nation as “the pet rock of this era.” I was immediately taken to task and told to defend this statement.

The argument I was given went about like this.

If one is an expert at poker, one can expect to win consistently. That’s much more than you can hope to get from other games of chance like blackjack or craps, so why would anyone lose interest in poker, given the unwavering popularity of those games?

Forget that it’s on television; once you’re into poker, I think you are hooked for life.

First let me say that I am not backing my response with any hard data. This is purely an academic exercise.

Poker suffers from an important handicap: it is necessarily worse than a zero-sum game. The winners are few, and in large tournaments or online walk away with somewhat less than what the losers have given up.

The idea that an adroit player can consistently come out the better appears to be all-too-true. But rather than being an asset, this is the very reason why poker will not continue in popularity. For every player that wins consistently, there are players who lose just as consistently.

These players plainly will not be interested indefinitely. They have sprouted like reeds from the Nile-esque deluge of ESPN coverage for the time being; in fact, this is making it significantly easier to be one of the lucky few who leave with chips.

When the plebeian interest wanes, the game’s talent bar will steadily rise. Ultimately, nearly all of those who currently style themselves as among the upper echelons will look around only to see that they are in free fall.

This kind of analysis is not difficult to derive; why is it that so few take the trouble to do it?

Tags: , ,
Posted in Eccentric | No Comments »