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GPUs, Monte Carlo Simulation and Kooderive with Mark Joshi - February 25-27th Mathfinance Conference 2015

Understanding Uncertainty's Blog

 

Probability and stats in GCSE Maths

August 4, 2013 Comments (0)

The current consultation on GCSE subject content and assessment objectives for Mathematics GCSE features major changes for probability and statistics. I encourage everyone with an interest to respond (before 20th August): here is my personal take on the topic. The proposals are as follows: Probability record and describe the frequency of outcomes of probability experiments using tables and frequency trees apply ideas of randomness, fairness and equally likely events to calculate expected...

Fatality risk on Boris-bikes?

July 7, 2013 Comments (0)

I was saddened by the death on Friday of a Boris-bike rider in Whitechapel High Street, particularly as I am a frequent and enthusiastic user of the scheme. But as a statistician, I also immediately wonder about the risks of riding these bikes. Transport for London report that between December 2010 and 31st May 2013 there were around 22,000,000 Barclays Cycle Hire (the official name) trips in London. There were 750,000 trips in May, so let’s assume that by July 7th there were around 23,000,000...

Speed cameras, regression-to-the-mean, and the Daily Mail (again)

June 7, 2013 Comments (0)

It was interesting to hear ‘regression-to-the-mean’ being discussed on the Today programme this morning, even if the quality of the debate wasn’t great. The issue was the effectiveness of speed cameras, which tend to get installed after a spate of accidents. Since bad luck does not last, accidents tend to fall after such a ‘blip’, and this fall is generally attributed to the speed camera, whereas it would have happened anyway: this is what is meant by ‘regression-to-the-mean’. The report from...

How can 2% become 20%? Ask the Daily Mail.

June 4, 2013 Comments (0)

The Daily Mail’s headline below is unequivocal – statins cause a 20% increase in muscle problems. Unfortunately, the ‘20%’ is complete nonsense - the study on which this story is based claims that taking statins increased the risk of muscle problems from 85% to 87%. And even that claim is highly dubious. How can the Daily Mail get it so wrong? The ‘20%’ is a basic statistical error promoted by a misleading abstract and press release from JAMA Internal Medicine – associated with the...

Court of Appeal bans Bayesian probability (and Sherlock Holmes)

February 25, 2013 Comments (0)

..when you have eliminated the impossible, whatever remains, however improbable, must be the truth (Sherlock Holmes in The Sign of the Four, ch. 6, 1890) In a recent judgement the English Court of Appeal has not only rejected the Sherlock Holmes doctrine shown above, but also denied that probability can be used as an expression of uncertainty for events that have either happened or not. The case was a civil dispute about the cause of a fire, and concerned an appeal against a decision in the...

What's more dangerous - the bute or the burger?

February 15, 2013 Comments (0)

There is reasonable public outrage at possible criminal conspiracies to adulterate meat products with horsemeat, and additional concerns raised about the presence of the anti-inflammatory known as bute. While not in any way questioning this concern about adulteration with a chemical compound, it is helpful to get a sense of magnitude. When bute was given as a human medicine, was reported to be associated with a serious adverse reaction in 1 in 30,000 (over a whole course of treatment), but at...

Squaring the square, in glass

January 22, 2013 Comments (0)

Here is my latest stained glass effort, seen on a snowy day. It is a 'square of squares', where all the constituent squares are of different sizes. Here are the dimensions - It is copied from the logo of the Trinity Mathematical Society, who point out that it is the unique smallest simple squared square (smallest in that it uses the fewest squares, and simple in that no proper subset of the squares of size at least 2 forms a rectangle). It was proved to be the smallest such square by...

Alcohol in pregnancy and IQ of children

November 27, 2012 Comments (0)

Some of the coverage of yesterday's story about drinking in pregnancy and IQ of children was not entirely accurate. The Times reported that 'women who drink even a couple of glasses of wine a week during pregnancy are risking a two-point drop in their child's IQ', and 'children whose mothers drank between 1 and 6 units a week - up to three large glasses of wine - had IQs about two points lower '(than mothers who did not drink). But let's look at Table 3 of the paper, which is available here....

More lessons from L'Aquila

October 28, 2012 Comments (0)

The L’Aquila story gets even murkier. Scientists duty Additional reports suggest complicity to manipulate public opinion. See, for example, this article in La Repubblica (in Italian) with the headline quote 'the truth cannot be said' taken from a tapped telephone call between the head of the Civil Protection Agency and one of the scientists. The article claims that the misleading statement on which the trial hinged - that the many small shocks reduced rather than increased the risk - had...

The Continuing Tragedy of L’Aquila

October 24, 2012 Comments (0)

As in ‘Boffins jailed for not predicting earthquake’, the 6-year sentences and massive fines handed out to the Italian seismologists have been largely portrayed by the media and commentators outside Italy as an attack on science, and the prosecution ridiculed as expecting the scientists to have been able to predict the earthquake. However, many have pointed out that it is all a bit more complicated than that. See, for example, a detailed article in Nature and these blogs by Roger Pielke and...