mathematics

Bob

5 February 2015

Last year I wrote on a couple of occasions about the Sleeping Beauty problem. The problem raises some tricky questions and I did promise to attempt to answer the questions, which I am yet to do. Only last week, I was discussing the problem again with my friend Giulio, whose paper on the subject I published […]

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Sleeping Beauty – a “halfer” approach

29 September 2014

If you read the last post on the Sleeping Beauty problem, you may recall I did not pledge allegiance to either the “halfer” or the “thirder” camp, because I was still thinking my position through. More than a month later, I still can’t say I am satisfied. Mathematically, the thirder position seems to be the […]

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Sleeping Beauty

26 August 2014

For the last couple of weeks, I have fallen asleep thinking about Sleeping Beauty. Not the heroine of the Charles Perrault fairy tale, or her Disney descendant, but the subject of a thought experiment first described in print by philosopher Adam Elga as follows: Some researchers are going to put you to sleep. During the two days […]

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Randomness revisited (mathsy)

21 April 2014

My recent randomness post hinged on people’s expectations of how long a run of heads or tails you can expect to see in a series of coin tosses. In the post, I suggested that people tend to underestimate the length of runs, but what does the fox maths say? The exploration of the numbers in this post draws on […]

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Randomness

6 April 2014

With three children, I have my own laboratory at home for performing psychological experiments. Before anyone calls social services, there is an ethical committee standing by (their mother). This evening, I tried out one of my favourites: testing the perception of randomness. Here is the setup: I gave the boys two pieces of paper and […]

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Benford’s Law

16 April 2012

Here is a quick quiz. If you visit the Wikipedia page List of countries by GDP, you will find three lists ranking the countries of the world in terms of their Gross Domestic Product (GDP), each list corresponding to a different source of the data. If you pick the list according to the CIA (let’s […]

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More colour wheels

6 November 2011

In response to my post about colour wheels, I received a suggested enhancement from Drew. The idea is to first match colours based on the text provided and then add nearby colours. This can be done by ordering colours in terms of hue, saturation, and value. The result is a significant improvement and it will capture all of […]

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Colour wheels in R

5 November 2011

Regular readers will know I use the R package to produce most of the charts that appear here on the blog. Being more quantitative than artistic, I find choosing colours for the charts to be one of the trickiest tasks when designing a chart, particularly as R has so many colours to choose from. In […]

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Natural frequencies

22 October 2010

In my last post, I made a passing reference to Gerd Gigerenzer’s idea of using “natural frequencies” instead of probabilities to make assessing risks a little easier. My brief description of the idea did not really do justice to it, so here I will briefly outline an example from Gigerenzer’s book Reckoning With Risk. The […]

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The Mule goes SURFing

30 July 2010

A month ago I posted about “SURF”, the newly-established Sydney R user forum (R being an excellent open-source statistics tool). Shortly after publishing that post, I attended the inaugural forum meeting. While we waited for attendees to arrive, a few people introduced themselves, explaining why they were interested in R and how much experience they […]

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