Blog Archives

Bayesian First Aid: Pearson Correlation Test

March 17, 2014
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Bayesian First Aid: Pearson Correlation Test

Correlation does not imply causation, sure but, as Edward Tufte writes, “it sure is a hint.” The Pearson product-moment correlation coefficient is perhaps one of the most common ways of looking for such hints and this post describes the Bayesian First Aid alternative to the classical Pearson correlation test. Except for being based on Bayesian estimation (a good...

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A Hack to Create Matrices in R, Matlab style

March 7, 2014
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A Hack to Create Matrices in R, Matlab style

The Matlab syntax for creating matrices is pretty and convenient. Here is a 2x3 matrix in Matlab syntax where , marks a new column and ; marks a new row:Here is how to create the corresponding matrix in R:matrix(c(1,4,2,5,3,6), 2, 3)## ## 1...

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Oldies but Goldies: Statistical Graphics Books

March 1, 2014
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Oldies but Goldies: Statistical Graphics Books

I just wanted to plug for three classical books on statistical graphics that I really enjoyed reading. The books are old (that is, older than me) but still relevant and together they give a sense of the development of exploratory graphics in general and the graphics system in R specifically as all three books were written at Bell Labs...

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Bayesian First Aid: Two Sample t-test

February 24, 2014
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Bayesian First Aid: Two Sample t-test

As spring follows winter once more here down in southern Sweden, the two sample t-test follows the one sample t-test. This is a continuation of the Bayesian First Aid alternative to the one sample t-test where I’ll introduce the two sample alternative. It will be a quite short post as the two sample alternative is just more of...

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A Significantly Improved Significance Test. Not!

February 12, 2014
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A Significantly Improved Significance Test. Not!

It is my great pleasure to share with you a breakthrough in statistical computing. There are many statistical tests: the t-test, the chi-squared test, the ANOVA, etc. I here present a new test, a test that answers the question researchers are most anxious to figure out, a test of significance, the significance test. While a test like the two...

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Bayesian First Aid: One Sample and Paired Samples t-test

February 4, 2014
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Bayesian First Aid: One Sample and Paired Samples t-test

Student’s t-test is a staple of statistical analysis. A quick search on Google Scholar for “t-test” results in 170,000 hits in 2013 alone. In comparison, “Bayesian” gives 130,000 hits while “box plot” results in only 12,500 hits. To be honest, if I had to choose I would most of the time prefer a notched boxplot to...

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Announcing pingr: The R Package that Sounds as it is Called

January 26, 2014
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Announcing pingr: The R Package that Sounds as it is Called

pingr is an R package that contains one function, ping(), with one purpose: To go ping on whatever platform you are on (thanks to the audio package). It is intended to be useful, for example, if you are running a long analysis in the background and want to know when it is ready. It’s also useful if...

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Bayesian First Aid: Binomial Test

January 20, 2014
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Bayesian First Aid: Binomial Test

The binomial test is arguably the conceptually simplest of all statistical tests: It has only one parameter and an easy to understand distribution for the data. When introducing null hypothesis significance testing it is puzzling that the binomial test is not the first example of a test but sometimes is introduced long after the t-test and the ANOVA...

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Bayesian First Aid

January 10, 2014
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Bayesian First Aid

So I have a secret project. Come closer. I’m developing an R package that implements Bayesian alternatives to the most commonly used statistical tests. Yes you heard me, soon your t.testing days might be over! The package aims at being as easy as possible to pick up and use, especially if you are already used to the classical .test...

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An Animation of the Construction of a Confidence Interval

December 30, 2013
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An Animation of the Construction of a Confidence Interval

I’m playing blog ping-pong with John Kruschke’s Doing Bayesian Data Analysis blog as he was partly inspired by my silly post on Bayesian mascots when writing a nice piece on Icons for the essence of Bayesian and frequentist data analysis. That piece, in turn, inspired me resulting in the following wobbly backhand.The confidence interval...

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