Archives (6)

An interestesting video from the Geography department at the University of Minnesota. The cellist, Minnesota student Daniel Crawford, plays the historical earth mean temperature record converted to music

One difficulty with sonic display of data is scaling: the video uses a semitone for 0.03 Celsius, but that seems like quite a big pitch change for a barely-measurable temperature difference.  The scaling gives a range of three octaves (rather more than a typical singers voice) for just over 1 degree, which is a meaningful but not catastrophic change in temperature.  I think it’s fair to say the pitch scaling is a bit exaggerated.

It’s hard to say what would be appropriate, since we don’t have the research and practical experience that informs axis choices for graphs.  One approach might be to take advantage of vibrato in cello performance, and scale so that the minimum measurement uncertainty is the same as the vibrato variation.  The Google suggests that cello vibrato is about 1/5 to 1/4 semitone, and mapping this to a minimum confidence interval width (from the Berkeley data) of 0.04C gives a scaling of 0.16 to 0.2 degrees per semitone, or a total range for the whole piece of about half an octave.

From itnews

A mobility programme using Apple iPhones and iPads has changed the way New Zealand Police officers work, and the force is partly attributing a sharp drop in crime to the rollout of the devices.

According to figures published by NZ Police, using the devices within the Policing Excellence programme [PDF] has contributed to a 13 per cent reduction in crime for the year to May 31.

The Police press release is here, and you can see that they are the source of the claims. But if you look at the linked PDF, the 13% reduction is based on comparing (partly provisional) data for June 2012-May 2013 and June 2008-May 2009.  Crime has been decreasing steadily over this time: here’s the graph for 1995-2012 from NZ police (PDF, p16)

The decrease from fiscal year 2008/9 to fiscal year 2011/12 (before the iPads) is from 1031.9 per 10,000 population to 891.9 per 10,000 population, or just over 14% — slightly larger than the decrease claimed when the iPad revolution is included.

It’s not surprising that the new mobility initiative isn’t showing up clearly in crime figures yet — the devices are still being rolled out. In fact the NZ Police report is talking about their whole modernisation initiative (started in August 2010) , though it’s still not possible to say how much of the 13% decrease is due to the changes, and the overall downward trend in crime would be sufficient to explain the entire decrease.

• According to the Guardian, data journalism is improving rapidly.  The story is about the second Data Journalism awards, from the Global Editors Network
• Comparing the quality of randomized trial reports in medicine and economics (from a U of Otago economist)

I’ve commented on several occasions that it would be great if science journalism was as good as sports journalism.  Here’s a more-detailed quote from Noam Chomsky on the same issue

When I’m driving, I sometimes turn on the radio and I find very often that what I’m listening to is a discussion of sports. These are telephone conversations. People call in and have long and intricate discussions, and it’s plain that quite a high degree of thought and analysis is going into that. People know a tremendous amount. They know all sorts of complicated details and enter into far-reaching discussion about whether the coach made the right decision yesterday and so on. These are ordinary people, not professionals, who are applying their intelligence and analytic skills in these areas and accumulating quite a lot of knowledge and, for all I know, understanding. On the other hand, when I hear people talk about, say, international affairs or domestic problems, it’s at a level of superficiality that’s beyond belief.

(via Chad Orzel, who thinks there’s a snappier version of this out there, but can’t find it)

Team Ratings for Round 17

Here are the team ratings prior to Round 17, along with the ratings at the start of the season. I have created a brief description of the method I use for predicting rugby games. Go to my Department home page to see this.

Performance So Far

So far there have been 118 matches played, 72 of which were correctly predicted, a success rate of 61.02%.

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.

Team Ratings for Round 19

This year the predictions have been slightly changed with the help of a student, Joshua Dale. The home ground advantage now is different when both teams are from the same country to when the teams are from different countries. The basic method is described on my Department home page.

Here are the team ratings prior to Round 19, along with the ratings at the start of the season.

Performance So Far

So far there have been 108 matches played, 75 of which were correctly predicted, a success rate of 69.4%.

Here are the predictions for last week’s games.

Predictions for Round 19

Here are the predictions for Round 19. 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.