Posts filed under General (1162)

May 26, 2017

In memoriam Alastair Scott

AlastairScott4-560x373(Alastair didn’t contribute directly to StatsChat, but he was a major contributor to this being a department that would take it seriously.)

In memoriam: Alastair Scott, Emeritus Professor of Statistics (1939-2017).

Alastair Scott, one of the finest statisticians New Zealand has produced, died in Auckland, New Zealand on Thursday, May 25. He served the University of Auckland with distinction from 1972 to 2005.

His research was characterised by deep insight and he made pioneering contributions across a wide range of statistical fields. Alastair was acknowledged, in particular, as a world leader in survey sampling theory and the development of methods to efficiently obtain and analyse data from medical studies. His methods are applied in a wide range of areas, notably in public health. Beyond research, he contributed prolifically to the statistical profession in academia, government, and society.

Alastair was a Fellow of the Royal Society of New Zealand, the American Statistical Association, the Institute of Mathematical Statistics, the Royal Statistical Society, and an honorary life member of the New Zealand Statistical Association. In November last year, Alastair was awarded the Royal Society of New Zealand’s Jones Medal, which recognised his lifetime contribution to the mathematical sciences.

Alastair gained his first degrees at the University of Auckland: BSc in Mathematics in 1961 and MSc in Mathematics in 1962. After a period at the New Zealand Department of Scientific and Industrial Research, he pursued a PhD in Statistics at the University of Chicago, graduating in 1965. He then worked at the London School of Economics from 1965-1972.

Alastair returned to New Zealand in 1972 to a post in what was then the Department of Mathematics and Statistics at the University of Auckland; he and wife Margaret had decided that they wanted to raise their children, Andrew and Julie, in New Zealand. Throughout his career, Alastair was regularly offered posts at prestigious universities overseas, but turned them down. However, he held visiting positions at Bell Labs, the universities of North Carolina, Wisconsin, and UC Berkeley in the US, and at the University of Southampton in the UK.

In 1994, the University’s statistics staff, led by Professor George Seber, had a very amicable divorce from the Department of Mathematics and Statistics, and Alastair became the head of the new Department of Statistics. He helped set the tone for the department that still exists – hard-working, but welcoming, and social. The Department of Statistics is now the largest such school in Australasia.

In 2005, Alastair officially retired. A conference in Auckland that year in his honour attracted the largest concentration of first-rank international statisticians in New Zealand in one place at one time. Alastair kept an office in the department and continued writing and advising, coming into work almost every day.

Alastair Scott was an influential teacher and generous mentor to several generations of statisticians who valued his sage advice coupled with his trademark affability. Alastair had a full life professionally and personally. He was a wonderful teacher, mentor, colleague, and friend. We will all miss him greatly and we extend our sincere condolences to Margaret, Andrew and Julie, and his family, friends, and colleagues all over the world.

 

May 23, 2017

Super 18 Predictions for Round 14

Team Ratings for Round 14

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.

Current Rating Rating at Season Start Difference
Hurricanes 18.33 13.22 5.10
Crusaders 14.42 8.75 5.70
Highlanders 11.19 9.17 2.00
Lions 9.87 7.64 2.20
Chiefs 8.46 9.75 -1.30
Blues 3.12 -1.07 4.20
Brumbies 1.66 3.83 -2.20
Stormers 1.04 1.51 -0.50
Sharks 1.00 0.42 0.60
Waratahs -0.33 5.81 -6.10
Jaguares -4.04 -4.36 0.30
Bulls -5.55 0.29 -5.80
Force -9.93 -9.45 -0.50
Reds -10.32 -10.28 -0.00
Cheetahs -10.95 -7.36 -3.60
Kings -12.44 -19.02 6.60
Rebels -15.37 -8.17 -7.20
Sunwolves -17.26 -17.76 0.50

 

Performance So Far

So far there have been 102 matches played, 79 of which were correctly predicted, a success rate of 77.5%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Chiefs vs. Crusaders May 19 24 – 31 -5.80 TRUE
2 Stormers vs. Blues May 19 30 – 22 1.10 TRUE
3 Hurricanes vs. Cheetahs May 20 61 – 7 30.40 TRUE
4 Force vs. Highlanders May 20 6 – 55 -12.80 TRUE
5 Sunwolves vs. Sharks May 20 17 – 38 -13.30 TRUE
6 Kings vs. Brumbies May 20 10 – 19 -10.30 TRUE
7 Lions vs. Bulls May 20 51 – 14 16.50 TRUE
8 Waratahs vs. Rebels May 21 50 – 23 17.40 TRUE

 

Predictions for Round 14

Here are the predictions for Round 14. 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.

Game Date Winner Prediction
1 Blues vs. Chiefs May 26 Chiefs -1.80
2 Reds vs. Force May 26 Reds 3.10
3 Sunwolves vs. Cheetahs May 27 Cheetahs -2.30
4 Highlanders vs. Waratahs May 27 Highlanders 15.50
5 Rebels vs. Crusaders May 27 Crusaders -25.80
6 Bulls vs. Hurricanes May 27 Hurricanes -19.90
7 Sharks vs. Stormers May 27 Sharks 3.50
8 Jaguares vs. Brumbies May 27 Brumbies -1.70
9 Lions vs. Kings May 28 Lions 25.80

 

NRL Predictions for Round 12

Team Ratings for Round 12

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.

Current Rating Rating at Season Start Difference
Broncos 7.78 4.36 3.40
Storm 7.07 8.49 -1.40
Sharks 6.10 5.84 0.30
Raiders 4.86 9.94 -5.10
Sea Eagles 3.25 -2.98 6.20
Roosters 3.13 -1.17 4.30
Cowboys 1.65 6.90 -5.30
Dragons 1.48 -7.74 9.20
Panthers 0.45 6.08 -5.60
Titans -1.68 -0.98 -0.70
Eels -2.44 -0.81 -1.60
Bulldogs -3.05 -1.34 -1.70
Rabbitohs -4.05 -1.82 -2.20
Warriors -5.59 -6.02 0.40
Wests Tigers -8.31 -3.89 -4.40
Knights -12.69 -16.94 4.20

 

Performance So Far

So far there have been 88 matches played, 50 of which were correctly predicted, a success rate of 56.8%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Sharks vs. Cowboys May 18 18 – 14 8.80 TRUE
2 Warriors vs. Dragons May 19 14 – 30 -0.70 TRUE
3 Broncos vs. Wests Tigers May 19 36 – 0 16.60 TRUE
4 Titans vs. Sea Eagles May 20 10 – 30 2.00 FALSE
5 Eels vs. Raiders May 20 16 – 22 -3.30 TRUE
6 Knights vs. Panthers May 21 20 – 30 -9.60 TRUE
7 Bulldogs vs. Roosters May 21 18 – 24 -1.90 TRUE
8 Rabbitohs vs. Storm May 21 6 – 14 -7.50 TRUE

 

Predictions for Round 12

Here are the predictions for Round 12. 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.

Game Date Winner Prediction
1 Rabbitohs vs. Eels May 26 Rabbitohs 1.90
2 Warriors vs. Broncos May 27 Broncos -9.40
3 Sharks vs. Bulldogs May 27 Sharks 12.60
4 Raiders vs. Roosters May 28 Raiders 5.20

 

May 20, 2017

Bright sunshiny day

Q: Isn’t Study suggests we need this first-thing in the morning a perfect example of click-bait?

A: Impressive. And what is this?

Q: This is daylight.

A: Makes sense.  And fits with the picture of someone stretching after getting out of bed.

Q: Does it fit the research?

A: Um.  Not so much. (link)

Q: Not people?

A: No, it was people. It’s just it was light exposure in office buildings.

Q: And these buildings weren’t where people slept?

A: No, that would be potentially inappropriate. It was where they worked.

Q: But giving people more light helped with sleep and depression?

A: “the study did not include a lighting intervention”

Q: So they compared people who had offices with windows and natural light to everyone else?

A: Basically.

Q: And there was a difference in how much sleep they got?

A: No.

Q: In whether they woke up a lot?

A: Not really. The ‘sleep efficiency’ was pretty much the same.

Q: In what, then?

A: In how long they took to fall asleep.

Q: And the depression and stress?

A: Well, the differences were statistically detectable, but they weren’t all that big.

Q: But wouldn’t you expect people with windows in their offices to be happier?

A: Yes. It’s a bit surprising how small the differences were in this study.

Q: So the headline is a bit exaggerated?

A: It’s worse than that. The headline says the research is about what you should have been doing, but it’s actually about what your employer should be doing.

May 17, 2017

Briefly

  • From the NY Times: In a survey of geographical knowledge and attitudes to North Korea, Americans who can tell their arse from their elbow are more likely to favour diplomacy.  This is different from the Agrabah question, because survey participants aren’t being lied to.
  • Perceptions of bias — more precisely, claims about perceptions of bias — are very different between Democrats and Republicans in the US, according to analysis at 538.  Democrats are likely to say they think whites and Christians don’t get discriminated against much but blacks, Muslims, immigrants, gays & lesbians do. For all the groups, about a third of Republicans say they think there’s a lot of discrimination.
  • Difficulties with doing randomised experiments on social issues, from the Brookings Institution.  One of the big problems is that there isn’t good theory to allow the results of an experiment to be generalised, in contrast to drug trials where we have a pretty reasonable idea of what it means when a drug does well in a randomised trial population.  A lot of the difficulties do generalise to public health interventions, though. On a related note, economist Noah Smith talks about the role of theory and experiment in economics and in science.
  • I wrote last year about judges interrupting each other in the US Supreme Court and whether it depended on gender — the analysis in the media had ignored how much each judge talked.  There’s now an analysis with more variables (and now the right link), and the gender difference looks stronger.
May 16, 2017

Super 18 Predictions for Round 13

Team Ratings for Round 13

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.

Current Rating Rating at Season Start Difference
Hurricanes 16.70 13.22 3.50
Crusaders 14.56 8.75 5.80
Highlanders 9.02 9.17 -0.10
Lions 8.64 7.64 1.00
Chiefs 8.54 9.75 -1.20
Blues 3.53 -1.07 4.60
Brumbies 1.74 3.83 -2.10
Stormers 0.63 1.51 -0.90
Sharks 0.54 0.42 0.10
Waratahs -0.91 5.81 -6.70
Jaguares -4.04 -4.36 0.30
Bulls -4.32 0.29 -4.60
Force -7.76 -9.45 1.70
Cheetahs -9.53 -7.36 -2.20
Reds -10.32 -10.28 -0.00
Kings -12.52 -19.02 6.50
Rebels -14.79 -8.17 -6.60
Sunwolves -16.80 -17.76 1.00

 

Performance So Far

So far there have been 94 matches played, 71 of which were correctly predicted, a success rate of 75.5%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Blues vs. Cheetahs May 12 50 – 32 16.90 TRUE
2 Brumbies vs. Lions May 12 6 – 13 -2.30 TRUE
3 Crusaders vs. Hurricanes May 13 20 – 12 -3.50 FALSE
4 Rebels vs. Reds May 13 24 – 29 -0.40 TRUE
5 Bulls vs. Highlanders May 13 10 – 17 -9.70 TRUE
6 Kings vs. Sharks May 13 35 – 32 -11.30 FALSE
7 Jaguares vs. Force May 13 6 – 16 10.10 FALSE

 

Predictions for Round 13

Here are the predictions for Round 13. 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.

Game Date Winner Prediction
1 Chiefs vs. Crusaders May 19 Crusaders -2.50
2 Stormers vs. Blues May 19 Stormers 1.10
3 Hurricanes vs. Cheetahs May 20 Hurricanes 30.20
4 Force vs. Highlanders May 20 Highlanders -12.80
5 Sunwolves vs. Sharks May 20 Sharks -13.30
6 Kings vs. Brumbies May 20 Brumbies -10.30
7 Lions vs. Bulls May 20 Lions 16.50
8 Waratahs vs. Rebels May 21 Waratahs 17.40

 

NRL Predictions for Round 11

Team Ratings for Round 11

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.

Current Rating Rating at Season Start Difference
Storm 7.03 8.49 -1.50
Sharks 6.54 5.84 0.70
Broncos 6.27 4.36 1.90
Raiders 4.62 9.94 -5.30
Roosters 2.76 -1.17 3.90
Sea Eagles 1.55 -2.98 4.50
Cowboys 1.21 6.90 -5.70
Panthers 0.41 6.08 -5.70
Dragons 0.27 -7.74 8.00
Titans 0.01 -0.98 1.00
Eels -2.20 -0.81 -1.40
Bulldogs -2.68 -1.34 -1.30
Rabbitohs -4.01 -1.82 -2.20
Warriors -4.38 -6.02 1.60
Wests Tigers -6.81 -3.89 -2.90
Knights -12.65 -16.94 4.30

 

Performance So Far

So far there have been 80 matches played, 43 of which were correctly predicted, a success rate of 53.8%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Bulldogs vs. Cowboys May 11 14 – 30 2.50 FALSE
2 Dragons vs. Sharks May 12 14 – 18 -2.50 TRUE
3 Wests Tigers vs. Rabbitohs May 12 8 – 28 4.50 FALSE
4 Panthers vs. Warriors May 13 36 – 28 9.00 TRUE
5 Storm vs. Titans May 13 36 – 38 12.90 FALSE
6 Sea Eagles vs. Broncos May 13 14 – 24 0.50 FALSE
7 Knights vs. Raiders May 14 34 – 20 -18.70 FALSE
8 Roosters vs. Eels May 14 48 – 10 3.20 TRUE

 

Predictions for Round 11

Here are the predictions for Round 11. 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.

Game Date Winner Prediction
1 Sharks vs. Cowboys May 18 Sharks 8.80
2 Warriors vs. Dragons May 19 Dragons -0.70
3 Broncos vs. Wests Tigers May 19 Broncos 16.60
4 Titans vs. Sea Eagles May 20 Titans 2.00
5 Eels vs. Raiders May 20 Raiders -3.30
6 Knights vs. Panthers May 21 Panthers -9.60
7 Bulldogs vs. Roosters May 21 Roosters -1.90
8 Rabbitohs vs. Storm May 21 Storm -7.50

 

May 10, 2017

Bombs away

Q: Did you see the Jagerbombs ‘as bad as taking cocaine’ headline in the Herald?

A: Doesn’t sound all that plausible. What’s a Jagerbomb? Is it like a Molotov cocktail?

Q: Apparently it’s Red Bull with Jägermeister.

A: Well, I don’t think I’m in any danger of drinking that.  How did you get the little dotty things over the ‘a’, by the way?

Q: If you hold down the ‘a’ key they pop up as an option (on a Mac). Like the Māori long vowels. But we nearly digress. Is a Jagerbomb really that dangerous?

A: Well, the story goes on to quote the researcher saying “I wondered if they were having a similar impact but to a lesser degree”

Q: And are they?

A: For suitable definitions of ‘same’ and ‘lesser’. And ‘were’.

Q: ಠ_ಠ

A: The research (no link given) looked at whether combining alcohol and energy drinks led to people getting injured more.

Q: That’s not the first thing you think of as a risk of taking cocaine. And how did they do the comparison? Recruit undergraduates with poor taste and give them Jagerbombs?

A: No

Q: You’re not going to say ‘mice’, are you?

A: No, what they did was go to the library and find all the previous studies of alcohol and energy drinks and injury, to review and summarise them.

Q: Is that useful?

A: It can be very useful. You can’t keep all that information in your head even if you’re a qualified Jagerbombologist.  Systematic reviews are a great innovation in modern medical research.

Q: So, how does the risk of injury compare to the risk with cocaine?

A: They didn’t look at that.

Q: Oh. Ok. So how big is the risk?

A: They didn’t come up with anything quantitative, because the previous research studies hadn’t been done in a similar enough way

Q: Did they come up with anything?

A: Yes, the results “suggest support for a relationship between increased risk of injury and [alcohol with energy drink] use”

Q: That’s not all that strong.

A: No.

Q: Was there a stronger relationship than just with alcohol on its own?

A: They say “some studies did not differentiate between injuries occurring in alcohol-only sessions relative to AmED sessions, making a comparison of the risk of injury between alcohol and AmED use impossible.

Q: Even if there is a difference, couldn’t it be that the sort of people who drink Jagerbombs or rum and Coke are different from people who drink beer, or cosmopolitans, or Sauv Blanc?

A: “Although the results remain mixed in terms of whether impulsivity or risk taking may moderate the relationship between AmED use and injury risk, there is enough evidence to warrant further exploration.”

Q: That all seems very reasonable.

A: The actual story isn’t too bad, either. Just the web-front-page headline.

Q: Wait, doesn’t the headline punctuation imply ‘as bad as taking cocaine’ is a quote? When it totally isn’t?

A: Yes. Yes, it does.

Briefly

  • “What CPE—and the field—needs now are analysts. Lots and lots of analysts. And we, at least, are hiring DataNerds who want to be JusticeNerds™. With departments now coming in by the state-load, we are inundated with confidential data that needs to be interrogated so that we can answer some of the most fundamental questions in policingfrom Phil Goff (no, not that one) at the Center for Policing Equity, via mathbabe.org
  • If someone claims your female developers are promoted less because they’re treated worse at code review, and you say “no, they’re treated worse because they’re more junior”, you’ve made the basic causal-inference error of conditioning on an intermediate consequence of your input variable.  Felix Salmon on Facebook’s example
  • “For too long social welfare has muddled along with bipartisan policies like shouting at the jobless or not helping people with mental health issues, without really checking if those methods work.” This, from, Lyndon Hood, isn’t going where you might expect.  It’s unfair, but not completely unfair.
  • Another reason ‘breakthrough’ science stories may be misleading: there was a research paper claiming fish preferentially eat microplastic pollution and are serious harmed by it. It has been retracted. There are allegations of deliberate fraud; the data were certainly not made available as the journal’s policy demanded.  If you remember a story on this, go back and see if the same media outlet covers the retraction.
  • I’ve written a few times about the bogus claim that the typical Kiwi pays no “net tax”.  In the other direction, there were stories about  “Tax Freedom Day” this week, on the basis of 34.8% of income going in tax. Yeah, nah.
  • Derek Lowe writes about a new analysis looking at solanezumab, Eli Lilly’s failed treatment for Alzheimer’s. The analysis claims that if the drug had been approved based on the early, weak signals of benefit, the cost to the US government would have been about ten billion dollars over the past four years. That would pay for a lot of trials, or for a lot of other improvements to dementia care.
  • There’s publication bias in research on stock-market patterns. Because of course there is.

This was almost too good to check


And this was too good to ask if it’s a joke:

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(it is)

May 9, 2017

Super 18 Predictions for Round 12

Team Ratings for Round 12

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.

Current Rating Rating at Season Start Difference
Hurricanes 17.39 13.22 4.20
Crusaders 13.87 8.75 5.10
Highlanders 9.17 9.17 0.00
Chiefs 8.54 9.75 -1.20
Lions 8.36 7.64 0.70
Blues 3.47 -1.07 4.50
Brumbies 2.02 3.83 -1.80
Sharks 1.40 0.42 1.00
Stormers 0.63 1.51 -0.90
Waratahs -0.91 5.81 -6.70
Jaguares -2.84 -4.36 1.50
Bulls -4.48 0.29 -4.80
Force -8.96 -9.45 0.50
Cheetahs -9.47 -7.36 -2.10
Reds -10.60 -10.28 -0.30
Kings -13.37 -19.02 5.70
Rebels -14.52 -8.17 -6.40
Sunwolves -16.80 -17.76 1.00

 

Performance So Far

So far there have been 87 matches played, 67 of which were correctly predicted, a success rate of 77%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Hurricanes vs. Stormers May 05 41 – 22 21.00 TRUE
2 Cheetahs vs. Highlanders May 05 41 – 45 -16.10 TRUE
3 Rebels vs. Lions May 06 10 – 47 -16.40 TRUE
4 Chiefs vs. Reds May 06 46 – 17 22.30 TRUE
5 Waratahs vs. Blues May 06 33 – 40 0.50 FALSE
6 Sharks vs. Force May 06 37 – 12 12.90 TRUE
7 Bulls vs. Crusaders May 06 24 – 62 -11.10 TRUE
8 Jaguares vs. Sunwolves May 06 46 – 39 19.50 TRUE

 

Predictions for Round 12

Here are the predictions for Round 12. 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.

Game Date Winner Prediction
1 Blues vs. Cheetahs May 12 Blues 16.90
2 Brumbies vs. Lions May 12 Lions -2.30
3 Crusaders vs. Hurricanes May 13 Hurricanes -3.50
4 Rebels vs. Reds May 13 Reds -0.40
5 Bulls vs. Highlanders May 13 Highlanders -9.70
6 Kings vs. Sharks May 13 Sharks -11.30
7 Jaguares vs. Force May 13 Jaguares 10.10