







Read the rest

Nate Silver's The Signal and The Noise

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Particle physicists not yet willing to call the election for Obama


Surviving a plane crash is surprisingly common

Between 1983 and 2000, more than 95% of people involved in plane crashes survived.

What Nate Silver is actually telling you about the election

The election is next week. And, with that in mind, Salon's Paul Campos has posted a helpful reminder explaining what the statistics at the fivethirtyeight blog actually mean (and what they don't).

In particular, you have to remember that, while Nate Silver gives President Obama a 77.4 percent chance of winning the presidential election, that's not the same thing as saying that Obama is going to win.

Suppose a weather forecasting model predicts that the chance of rain in Chicago tomorrow is 75 percent. How do we determine if the model produces accurate assessments of probabilities? After all, the weather in Chicago tomorrow, just like next week’s presidential election, is a “one-off event,” and after the event the probability that it rained will be either 100 percent or 0 percent. (Indeed, all events that feature any degree of uncertainty are one-off events – or to put it another way, if an event has no unique characteristics it also features no uncertainties).

The answer is, the model’s accuracy can be assessed retrospectively over a statistically significant range of cases, by noting how accurate its probabilistic estimates are. If, for example, this particular weather forecasting model predicted a 75 percent chance of rain on 100 separate days over the previous decade, and it rained on 75 of those days, then we can estimate the model’s accuracy in this regard as 100 percent. This does not mean the model was “wrong” on those days when it didn’t rain, any more than it will mean Silver’s model is “wrong” if Romney were to win next week.

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What a dead fish can teach you about neuroscience and statistics


And it is dead. Read the rest

What cancer statistics actually mean

Genius science writer Ed Yong used to work for a cancer charity, so he's seen how the cancer research sausages get made. In a new post at Not Exactly Rocket Science, Ed takes you on a brief tour of the factory, explaining why even good data doesn't necessarily mean what you think it means.

The post is based around a new study that says 16.1% of all cancers worldwide are caused by infections. This statistic is talking about stuff like HPV—viruses and other infections that can prompt mutations in the cells they infect. Sometimes, those mutations propagate and become a tumor.

That statistic tells us that infections play a role in more cancers than most laypeople probably think, Ed says. It gives us an idea of the scale of the problem. But you have to be careful not to read too much into that 16.1%.

The latest paper tells us that 16.1% of cancers are attributable to infections. In 2006, a similar analysis concluded that 17.8% of cancers are attributable to infections. And in 1997, yet another study put the figure at 15.6%. If you didn’t know how the numbers were derived, you might think: Aha! A trend! The number of infection-related cancers was on the rise but then it went down again.

That’s wrong. All these studies relied on slightly different methods and different sets of data. The fact that the numbers vary tells us nothing about whether the problem of infection-related cancers has got ‘better’ or ‘worse’. (In this case, the estimates are actually pretty close, which is reassuring.

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Why water supply affects your computer

Between now and 2020, the greatest increases in population growth in the United States are projected to happen in the places that have the biggest problems with fresh water availability. This isn't just a drinking water problem, or even an agriculture problem. It's an energy issue, too. Most of our electricity is made by finding various ways to boil water, producing steam that turns a turbine in an electric generator. In 2000, we used as much fresh water to produce electricity as we used for irrigation—each sector represented 39% of our total water use. (From a poster at Lawrence Berkeley National Laboratory.) Read the rest

Cybercrime sucks (for criminals)





Cybercrime as a Tragedy of the Commons Read the rest




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Danish trade minister and ACTA booster apologise for bogus piracy numbers

Here's a clip of a Danish TV show discussing ACTA, which Denmark has fiercely advocated in favor of. It starts with the head of a rightsholder society and the Danish trade minister quoting dodgy statistics about the extent and cost of piracy, and then demonstrates that these statistics are patently false, and finally, brings out those responsible for quoting them and gets them to admit their errors. Priceless.

You can see both the Danish Trade Minister and the head of a Danish music rights organization (and famous Danish musician) Ivan Pedersen appear on a TV show below (with English subtitles). On the show, a well-informed presenter focuses on how both of these ACTA defenders claimed that 95% of music downloaded in Denmark was unauthorized, and carefully shows how that's simply false -- and then gets both of the ACTA defenders to admit that the numbers were wrong.

Danish Trade Minister Apologizes For Using Bogus Industry Numbers To Support Pro-ACTA Argument Read the rest

Facebook's funny accounting has "active users" who never use Facebook

The NYT's Andrew Ross Sorkin quotes Barry Ritholtz's digging into how Facebook's IPO documents define "active" users and finds that many of them may never visit the site. Facebook counts you as "active" if your only involvement with the service is setting it up to republish your Twitter feed, or if you click "Like" buttons but never log in to the actual service. This should matter to investors, since Facebook earns no advertising revenue from those users, though it may earn some other income by reselling the private details of their browsing habits as gleaned from its tracking cookies.


“Think of what this means in terms of monetizing their ‘daily users,’ ” Barry Ritholtz, the chief executive and director for equity research for Fusion IQ, wrote on his blog. “If they click a ‘like’ button but do not go to Facebook that day, they cannot be marketed to, they do not see any advertising, they cannot be sold any goods or services.

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How deadly is bird flu?


But this might not be the full story.


However, they don't necessarily represent everybody who has contracted H5N1.



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Local snow does not disprove global climate change

Even with all those Snowpocalypseses(?), NASA says that 2011 was still the ninth warmest year on record since 1880—and all but one of the top 10 warmest years have happened in the last 11 years. 1998 is third-hottest, although it's worth noting that the top six years are all close enough that they may as well be fundamentally tied for first. Read the rest

The best set of infographics ever


Ryan Gosling's soulful eyes + smooth statistics

Biostatistics Ryan Gosling will look deeply into your eyes and ask about your p-value.

Via Jacquelyn Gill

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