Stats Chat

Team Ratings for Round 18

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 126 matches played, 74 of which were correctly predicted, a success rate of 58.7%.
Here are the predictions for last week’s games.

Predictions for Round 18

Here are the predictions for Round 18. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

From the Chronicle of Higher Education

Mr. Vijg said repeatedly that his Nature paper made no “definitive statement” about a maximum human age and that he felt “amazement” that anyone might think otherwise. But he acknowledged approving a news release about his study issued by Albert Einstein College with the headline: “Maximum human lifespan has already been reached, Einstein researchers conclude.”

It’s more often the press release than the research paper, but with the consent of the researchers. If press releases were signed by a researcher and made available along with the research paper, there’d be more incentive not to do this sort of thing.

• The Australian has a story about religion in Australia, with the figure of “a touch under 70 per cent nominating a religious affiliation.” That’s only true if you include the 10.6% “Religious affiliation not stated” as nominating a religious affiliation.  The true figure is 56.8%.  You could stretch that to 63.5% of those who answered, but that’s assuming (at least implicitly) that the no-answers are just as likely to be religious as those who stated an affiliation. (via John Quiggin)

• This is why 10 stunning photos will make you cry tears of joy.

• From the Dallas Morning News:Steve Doud, a subscriber from Plano, emailed me to say he’d read something in the June 21 Dallas Morning News that couldn’t possibly be true.An eight-paragraph Washington Post article on page 10A reported on a national study about kids and guns. The last sentence said 4.2 percent of American kids have witnessed a shooting in the past year.

• There’s news in the UK claiming that Ryanair’s “random” seat allocation for people who don’t pay extra to pick a set isn’t random and favours middle seats, including something from Oxford University statisticians. It’s clear that the seats are not a simple random sample of all seats on the plane, but that isn’t what Ryanair is claiming. The airline’s defence, that the people who pay to pick seats usually pick the better ones, seems pretty plausible to me.

• Buzzfeed says the US is going to spend $7.1 billion on food for the Fourth of July weekend. If you think about this as 321 million people for a weekend plus a holiday, it’s not as impressive.  Maybe they’re only counting some types of food?  This violates two of the three basic rules for big dollar numbers: they need to be per-capita, inflation-adjusted, and compared to something. (via Fred Clark)

• “A sloppy attitude towards statistics has led to exaggerated and unjustified claims becoming commonplace in science, according to one of Britain’s most eminent statisticians.” David Spiegelhalter, reported in the Guardian

And finally, a picture of one of the causes of overdiagnosis in cancer — and one of the causes of illusory improvements in survival from earlier screening.

What is overdiagnosis? This refers to the detection of cancers that would never cause harm: https://t.co/tEJ7I54a1z pic.twitter.com/VY8okHOL9q

— National Cancer Inst (@theNCI) June 30, 2017

Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.

Here’s how it works:

• Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday July 7 2017.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of July 1 – 7 2017 inclusive.
• Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.

Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.

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StatsChat has been going long enough that I can look back at stories I disparaged in the past and see how well they held up.

To begin with, an April 2012 story about a vaccine for heart disease that might be available within five years. It wasn’t.

There doesn’t seem to have been any real development of this vaccine. But there is a 2017  research paper that has a new promising approach to vaccinating against heart disease.

You might have seen a story in the Guardian (don’t click while you’re eating), headlined “Popularity of sushi has brought rise in parasitic infections, warn doctors“.

There’s a link (also not safe for dinner) to a single case report of anisakiasis in Portugal attributed to sushi. The case report says

Most of the cases were described in Japan due to food habits; however, it has been increasingly recognised in Western countries.2 ,3

If you follow those references, you find a report of 2 cases in Italy, due to marinated raw anchovies, and 25 cases in Spain, due to marinated raw anchovies.

Anisakiasis is now being diagnosed in western countries, but if we can believe the evidence behind this story the cases are mostly from traditional European food practices, not because of  sushi.

Q: Did you see cannabis is actually better for pain relief than opioids?

A: Not convinced.

Q: But 92%97% of patients said they preferred it! Even if they’d tried opioids! You’re not saying you know better than them, are you?

A: Imagine you had a survey of people who cycle to work, including lots of people who own cars.

Q: Ok.

A: What proportion of those people would say they’d choose to cycle to work instead of driving?

Q: I don’t know, I don’t drive.

A:  Imagine you had a survey of people who cycle to work, including lots of people who have perfectly good bus routes as alternatives.

Q: Ok.

A: What proportion of those people would say they’d choose to cycle to work instead of driving or taking the bus?

Q: A lot.

A: Maybe even 92%97%?

Q: Maybe.

A: The survey was of about 2000 current medical cannabis users. It’s not surprising they say it works.

Q: So it’s not true?

A: No, I think it quite like is true, or at least partly true — not for everyone, but for a lot of people.

Q: Then what’s the problem?

A: The survey provides almost no additional evidence that it’s true. I already thought it was plausible, but anyone who didn’t think that shouldn’t have had their mind changed by the survey.

Q: Ok, what would convince you? Do we need randomised trials?

A: That would be nice.

Q: And a pony?

A: Ok, ok.  More realistically, a cohort study that follows up a group of people starting to use cannabis for pain relief to find out what they end up preferring, rather than starting with people who prefer cannabis.  You could set that up somewhere were medical use was just being legalised, and it wouldn’t cost that much.

Team Ratings for Round 17

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 118 matches played, 71 of which were correctly predicted, a success rate of 60.2%.
Here are the predictions for last week’s games.

Predictions for Round 17

Here are the predictions for Round 17. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

• A map of 1.3 billion taxi trips in New York, taking advantage of the underappreciated principle that there’s no point having more detail than the screen can display.  Also, GPS error naturally gives an attractive glowing effect that you’d usually have to add in afterwards

• “In the summer of 2015, Alexandra Franco got a letter in the mail from a company she had never heard of called AcurianHealth. The letter, addressed to Franco personally, invited her to participate in a study of people with psoriasis, a condition that causes dry, itchy patches on the skin.”  A story about creepy data-mining, from Gizmodo.

• From Scientific American, graphics showing daily, weekly, yearly patterns in number of births.

• From the New York Times: a new drug for muscular dystrophy. It costs about US$1 million per year, and the FDA is not really convinced it has an effect

• It’s time for the NZ Garden Bird Survey, which means it’s time for me to recommend their questions and answers page for its attention to principles of experimental design.

• “Death when it comes will have no sheep”. Last week it was hamster names; this week it’s proverbs. Look, save yourself some effort and just go directly to Janelle Shane’s blog rather than waiting for each post to go viral.

• “In Science, probability is more certain than you think.” Chad Orzel

Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.

Here’s how it works:

• Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday June 30 2017.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of June 24 – 30 2017 inclusive.
• Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.

Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.

(more…)