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Showing posts from June, 2006

My two cents

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I'm a creature of habit. Each morning, upon arriving at the hospital where I work, I stop at the café. I always get the same size and type of coffee, and I know the price in advance. Surprisingly enough, today my coffee was 2 cents cheaper. Why? Well, the Conservative government has just lowered the goods and services tax (GST) by 1%. Of course the price difference on a cup of coffee is utterly trivial. (How long before we save everyone a lot of trouble and get rid of the penny altogether?) If I'd been buying a new car I might have saved a few hundred dollars. The Conservatives believe that this will stimulate the economy, and that may well be true, although I imagine that might take a little while. But in any case, that's an economic prediction, not a certainty. Economies don't always behave the way economic models suggest they will. (I'm being charitable.) Ultimately, it remains to be seen what will actually happen. If the economy does improve, the Conservatives w...

That question sucks!

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Andrew Gelman commented yesterday on a recent CBS News Poll which asked the following question: "Should U.S. troops stay in Iraq as long as it takes to make sure Iraq has a stable democracy, even if it takes a long time, or leave as soon as possible, even if Iraq is not completely stable?" Gelman points out that it's a "double-barrelled" question with "... the assumption that U.S. troops will 'make sure Iraq has a stable democracy,' along with the question of how long the troops should stay". He also notes that the New York Times piece on the poll included "a yucky graph (as Tufte would put it, 'chartjunk')", which I have shown here. It really doesn't get much better than this: an exceedingly slanted question and an exceedingly silly graph! If I may, I'd like to name it the bow tie graph ... but is that taken? On this, I defer to Kaiser over at Junk Charts . Dressing up simple percentages with multicoloured variable...

Another kind of nothing

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Missing values are the bane of the applied statistician. They haunt our data sets, invisible specters lurking malevolently. The missing value is like the evil twin of zero. The introduction of a symbol representing "nothing" was a revolutionary development in mathematics. The arithmetic properties of zero are straightforward and universally understood (except perhaps when it comes to division by zero, a rather upsetting idea). In comparison, the missing value has no membership in the club of numbers, and its properties are shrouded in mystery. The missing value was a pariah until statisticians reluctantly took it in— someone had to. And it's an ill-behaved tenant, popping in and out unexpectedly, sometimes masquerading as zero, sometimes carrying important messages—always a source of mischief. ... symbolizing nothing A variety of different symbols are used to represent missing values. The statistical software packages SAS and SPSS, for example, use a dot. The fact that i...

Of buffoonery and bigotry

Tonight is the New York City premiere of a documentary film called American Zeitgeist . The film's subtitle is "Crisis and conscience in an age of terror", and it looks fascinating. Following the screening—in fact as I write this—a debate is taking place between Eric Margolis and Christopher Hitchens . My friend Ray pointed this out, in passing, on his blog earlier this week , and I took the opportunity to comment on Christopher Hitchens. Here is an edited version of my comments: ———————— Part of me thinks that the best response to Christopher Hitchens is simply to ignore him. How anybody can consider him to be anything but a complete buffoon is beyond me. I think it's interesting to compare Christopher Hitchens and Ann Coulter. On the face of it, they're very different. Coulter is indisputably a joke (albeit a very nasty one), with no pretense of seriousness or intellect. Hitchens, on the other hand, has the sheen of intellec...