Posts from May 2023 (25)

From Newshub: New study into therapeutic cannabis finds 96pct of participants report benefits in medical conditions.

This is deeply unsurprising, as I pointed out when similar results came out in 2017.  People who keep on using cannabis therapeutically are likely to think it works, because otherwise they wouldn’t.

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 101 matches played, 56 of which were correctly predicted, a success rate of 55.4%.
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.

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 182 matches played, 132 of which were correctly predicted, a success rate of 72.5%.
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 Week 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 78 matches played, 61 of which were correctly predicted, a success rate of 78.2%.
Here are the predictions for last week’s games.

Predictions for Week 15

Here are the predictions for Week 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.

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.

Performance So Far

So far there have been 48 matches played, 28 of which were correctly predicted, a success rate of 58.3%.
Here are the predictions for last week’s games.

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.

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.

Performance So Far

So far there have been 96 matches played, 54 of which were correctly predicted, a success rate of 56.2%.
Here are the predictions for last week’s games.

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.

Team Ratings for Week 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 72 matches played, 55 of which were correctly predicted, a success rate of 76.4%.
Here are the predictions for last week’s games.

Predictions for Week 14

Here are the predictions for Week 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.

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.

Performance So Far

So far there have been 44 matches played, 27 of which were correctly predicted, a success rate of 61.4%.
Here are the predictions for last week’s games.

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.

This research, reported at Newshub, is pretty good: dogs are being evaluated for detecting Covid in reasonably large numbers of people at schools, and the results are actually published in a respectable peer-reviewed journal.  The numbers are still getting oversold a bit:

The study said [the dogs] were 83 percent accurate at identifying COVID-19-positive students, and 90 percent on the mark at picking out virus-negative students.

There are two issues here. First, 90% accuracy on virus-negative students is not at all good.  The current prevalence of Covid in NZ is maybe 1%, and the idea of dog-based-testing is for the subset of people who are possibly infected but apparently healthy, which will cut the numbers further.  Most of the people who test positive will be false positives, who will then need to be isolated for further testing.   Antigen tests have an accuracy in uninfected people (specificity) more like 99%.

Achieving 83% accuracy for identifying actual infections sounds good, and I’ve seen social media comments that it’s better than the antigen tests. It isn’t really: as the story says, the accuracy figure measures how well the dogs agree with the antigen tests.  83% accuracy means that the dogs are missing 17% of the infections that the antigen tests pick up.

If your school was doing regular testing of all students, this study suggests that you could reduce the amount of testing by using dogs to screen people first and only testing the kids who the dogs select. The accuracy would be lower than testing everyone, but it might be cheaper.   The study doesn’t really argue that dogs would be good on their own.

The story goes on to say

Dogs have also been using their powerful noses to detect other diseases such as cancer with shockingly high accuracy. 

Again, this is true (at least in a sense). Research studies, mostly small, have reported results of this sort for years. The fact that we aren’t currently using dogs to screen for any of these diseases suggests either that there are practical barriers to implementation, or that it doesn’t actually work all that well in practice.

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.

Performance So Far

So far there have been 88 matches played, 51 of which were correctly predicted, a success rate of 58%.
Here are the predictions for last week’s games.

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.