Pew Research have released a report on public opinion in Europe. There’s lots of important stuff in there about austerity, the Euro, unemployment, inequality, and so on. There’s also this entertaining table:
As Robert Burns didn’t quite write: O wad some Pew’R the giftie gie us, To see oursels as ithers see us!
Graeme Hill has sent in this clip from his Radio Live show on Sunday. Listen from about 4:30 until 7:00 elapsed.
He calls this quote from ONE News the “stupidest, most outrageous statistic I ever heard this week”:
“Experts say the odds of having two disasters like those in Boston and Texas in the same week are 1 in every 4,800 years.”
The statistic seems to have come from an ABC News story, but there’s no attribution there for the “experts” either.
Graeme Edgeler says on Twitter
I know many gay couples will want to marry quickly, but there *must* be a couple named Adam & Steve and we should totally let them go first.
Should we expect an Adam and Stephen couple? This is an opportunity to use public data and simple probability to get a rough estimate.
StatsNZ reported just over 5000 cohabiting male couples in 2006. That’s an underestimate of male couples, but probably an overestimate of those planning to marry soon.
I remembered seeing Project Steve, from the National Center for Science Education. They collect signatures supporting the teaching of evolution from scientists named Stephen (after Stephen J. Gould) — they are currently up to 1268 — and make the point that under 1% of US males are named Stephen.
It turns out that they get this information from the US Census. The most recent data is 1990 (and, of course, is US) so it’s not ideal, but it will give us a rough idea. Stephen comes in at 0.54%, and when you add in Stephan, Esteban, Stefano, it still is no more than 0.6%. Adam is 0.259%.
Under random assignment, then, there would be less than a 1 in 10 chance that there’s a couple called Adam and Steve living together in NZ, and even then they might well not be planning to get married.
[Update: Brendon correctly points out that I missed 'Steven', which is actually the most common variant. Apart from demonstrating that I'm an idiot, this doesn't change the basic message.]
I’m sure that many of our readers are familiar with the latest internet trend, the Harlem Shake. Recently, a statistical version appeared that demonstrates some properties of popular Markov Chain Monte Carlo (MCMC) algorithms. MCMC methods are computer algorithms that are used to draw random samples from probability distributions that might have complicated shapes and live in multi-dimensional spaces.
MCMC was originally invented by physicists (justifying my existence in a statistics department) and is particularly useful for doing a kind of statistics called “Bayesian Inference” where probabilities are used to describe degrees of certainty and uncertainty, rather than frequencies of occurrence (insert plug for STATS331, taught by me, here).
Anyway, onto the HarleMCMC shake. It begins by showing the Metropolis-Hastings method, which is very useful and quite simple to do, but can (in some problems) be very slow, which corresponds to the subdued mood at the beginning of a Harlem Shake. As the song switches into the intense phase, the method is replaced by the “Hamiltonian MCMC” method which can be much more efficient. The motion is much more intense and efficient after that!
Here is the original video by PhD students Tamara Broderick (UC Berkeley) and David Duvenaud (U Cambridge):
http://www.youtube.com/watch?v=Vv3f0QNWvWQ
Naturally, this inspired those of us who work on our own MCMC algorithms to create response videos showing that Hamiltonian MCMC isn’t the only efficient method! Within one day, NYU PhD student Daniel Foreman-Mackey had his own version that uses his emcee sampler. I also had a go using my DNest sampler, but it has not been set to music yet.
So, next time you read or hear about a great new MCMC method, you should ask the authors how well it performs on the “Harlem Shake Distribution”. Oh and thanks to Auckland PhD student Jared Tobin for linking me to the original video!
Most of the Stats department is currently moving from the leafy park-like north end of campus back to the glass and concrete Tower of Science. While we’re in transit, here’s a bogus poll on statistical terminology.
Distributions can be classified as to whether they produce more outliers or fewer outliers than a normal distribution. The terms are “platykurtic” (same Greek root as platypus, meaning “flat”) and “leptokurtic” (Greek root meaning “thin”)
Update: answer, and potentially discussion, in the comments
Usually when someone confuses the probability of A given B and the probability of B given A they don’t really understand that these are different, and you have to point it out and explain it carefully. Richard David Prosser manages to be self-refuting,
And he added: “If you are a young male, aged between say about 19 and about 35, and you’re a Muslim, or you look like a Muslim, or you come from a Muslim country, then you are not welcome to travel on any of the West’s airlines…”
He accepted that most Muslims are not terrorists, but said it’s “equally undeniable” that “most terrorists are Muslims”.
actually pointing out himself that p(terrorist|Muslim) and p(Muslim|terrorist) are not remotely similar. In the same way, although most members of the Pakistan cricket team are Muslims, most Muslims are not members of the Pakistan cricket team.
That doesn’t handle the further pointless complication of ‘people who look like Muslims’, who, as far as I have been able to tell, are not over-represented among terrorists, but this site might be helpful for calibration.
The Herald has a story about a new app called TalkTo. Rather than you calling a business and waiting around for a possibly unhelpful response, you can text TalkTo and wait for them to call the business, ask your question and pass on the unhelpful response. Or, at least, you can if the business is in the USA or Canada — they currently wouldn’t handle Novapay or Qantas, the two examples in the story. The app obviously wouldn’t help for issues that require a dialogue, which includes essentially all the time I spend on hold.
Anyway, the statistics angle is that we apparently spend 43 days on hold during our lives. As a basic numeracy challenge: is this more than you expect or less?
The number comes from 20 minutes per week for 60 years, so it doesn’t apply to any actually existing people — 60 years ago, we didn’t have the same level of on-hold, and 60 years in the future there’s at least some hope that a larger fraction of businesses will figure out how to make a useful web page (or whatever the next communication technology but seven turns out to be).
Remember the correlation between current chocolate consumption and all-time Nobel Prizes?
Two British researchers now have done the same exercise for current milk consumption. Their letter, in the journal Practical Neurology suggests (I hope not seriously) that vitamin D might be responsible. They used Messerli’s data on Nobel Prizes, and don’t seem to have noticed any of the problems with it.
As you will remember, we showed length of country name (per capita) was rather more strongly correlated with Nobel Prizes (per capita) than chocolate consumption, and it also beats milk consumption. It’s also much more convincing as a causal relationship: the country names are much more constant over the time the Nobel Prize data were accumulated than milk or chocolate consumption, and since there’s no plausible mechanism for wealthy countries to have longer names than poor countries we avoid economic confounding.
Stuff says (complete with cute photo)
The birth of a rare Nepalese red panda baby, weighing not much more than a tomato, has thrilled Auckland Zoo keepers.
Hmm.
Especially given all the fuss last year about New Zealanders’ ignorance of vegetables, perhaps “weighing a bit less than an iPhone” would be more informative.
