Posts from June 2019 (11)

Team Ratings for the Semi-finals

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 123 matches played, 83 of which were correctly predicted, a success rate of 67.5%.
Here are the predictions for last week’s games.

Predictions for the Semi-finals

Here are the predictions for the Semi-finals. 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.

The NZ Police have put out a report “based on the most frequent data requests made by members of the public under the Official Information Act and is organised according to the largest areas of demand that Police responds to.” (via Nat Dudley on Twitter)

That’s great. There are numbers and tables and graphical summaries.  Very useful.

On the other hand, this is typical of the graphs

The report has a lot of charts like this, showing trends over time.  They look as if they are using areas to depict the data, but they all have truncated y-axes that make the year-to-year variation look more dramatic.  The bottom 75% of this chart has gone missing.

If you want to use a truncated y-axis you can, with a line chart and axis designs that don’t make the bottom of the graph look as if it’s zero.  For example, patterns in the Keeling Curve of atmospheric CO₂ are more apparent if the whole range down to zero ppm isn’t shown. In this case, though, there’s no obvious benefit. It’s just misleading.

Team Ratings for the Quarter-finals

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 119 matches played, 79 of which were correctly predicted, a success rate of 66.4%.
Here are the predictions for last week’s games.

Predictions for the Quarter-finals

Here are the predictions for the Quarter-finals. 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.

Team Ratings for Round 15

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 108 matches played, 67 of which were correctly predicted, a success rate of 62%.
Here are the predictions for last week’s games.

Predictions for Round 15

Here are the predictions for Round 15. 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 Newsroom, via Giovanni Tiso on Twitter

Oranga Tamariki chief executive Gráinne Moss defended her agency’s actions around uplifts to Parliament’s social services committee on Wednesday morning, saying 98.5 percent of Māori children were not in care.

First, that’s a really unnatural way to describe a small percent…

No, first, 1.5% is not a small percentage when you’re talking about proportion of “children and young people in the care of the Chief Executive”. It is, or should be, a shockingly large percentage.  I went and checked it against the June 2017 figures, the most recent I could find with an ethnicity breakdown: the spreadsheet said 3518 Māori, 1538 Pākehā.  Comparing that to 2013 census figures of about 270,000 children and young people reporting Māori ethnicity we get 1.3%, and the total number in care has gone up from 5708 in June 2017 to 6350 in the most recent annual report, so 1.5% is plausible.  Graeme Edgeler was similarly motivated to check.

Given that, though, describing the figure as 98.5% not in care rather than 1.5% in care is really unnatural.  While zero kids in care is unrealistically optimistic, it’s at least a meaningful reference point; zero kids not in care is a dystopian nightmare. It makes more sense to use the percentage in care if you’re trying to communicate accurately.

Here are two barplots:

Of course, these figures alone can’t answer questions about racism at Oranga Tamariki. Someone would need to talk to their staff, children in their care, families who have been separated from those children, and so on.  Newsroom has been doing that.

Update: I have been pointed to this OIA response, which gives numbers by ethnicity (for yet another different breakdown of ethnicities).  I had apportioned the increase since 2017 in proportion to the 2017 numbers, but it has mostly been an increase in tamariki Māori in the care of OT.  The graphs are basically right, but reality is slightly worse than they show.

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 112 matches played, 73 of which were correctly predicted, a success rate of 65.2%.
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.

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.

Performance So Far

So far there have been 100 matches played, 63 of which were correctly predicted, a success rate of 63%.
Here are the predictions for last week’s games.

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.

Q: Did you see that married people only pretend to be happier than single people?

A: Where’s that?

Q: Newshub. Or the USA, depending on what you’re asking.

A: Yeah nah

Q: “Married people are happier than other population subgroups, but only when their spouse is in the room when they’re asked how happy they are. When the spouse is not present: f**king miserable,” Dolan said while speaking at a book festival in Wales.

A: I’m not sure we’re allowed to say “f**king” on StatsChat.

Q: But the survey data are right?

A: Up to a point

Q: That means no, doesn’t it?

A: The survey data are right, but the question wasn’t anything like what he thought

Q: How do you get a simple question about happiness wrong?

A: The question about the spouse being in the room

Q: Ok, how do you get that wrong?

A: The question was about marital status and living arrangements, and it wasn’t about a particular point in time when happiness was being measured (or even from the same survey).  The possible values included “Never Married”, “Married – Spouse Present”, “Married -Spouse Absent”, “Divorced”, “Separated”.

Q: Wait, so married people are actually f**king miserable if they’re not living with their spouse? A long-distance relationship, or going through a bad patch or something?

A: Yes, only “f**king miserable” is a bit of an exaggeration.  They’re still happier than divorced or never married people.

Q: Well, that’s f**king unsatisfactory

A: Indeed.  After the problem was pointed out to him, Professor Dolan has withdrawn that part of his claim

Q: But not Newshub

A: No.

• Data is Personal. What We Learned from 42 Interviews in Rural America. at Medium (via Andrew Gelman)
• Two posts on ways people display uncertainty in graphics (via Alberto Cairo)
• From Casey Fiesler Scientists Like Me Are Studying Your Tweets—Are You OK With That?
• Animated visualisation of what diseases were most studied over the past 70 years
• Story from the Sydney Morning Herald about weather forecasting, including new 3-week weather outlook predictions that the Bureau of Meteorology is planning to produce
• “Cancer drugs that speed onto the market based on encouraging preliminary studies often don’t show clear benefits when more careful follow-up trials are done,” from NPR
• Pharmac’s top-20 expenditures from last year.  For anyone who wants to have an opinion on how Pharmac should spend its budget.

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 105 matches played, 69 of which were correctly predicted, a success rate of 65.7%.
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.