Kendall’s Tau This is an example of Kendall’s Tau rank correlation.  This is similar to Spearman’s Rho in that it is a non-parametric measure of correlation on ranks.  It is an appropriate measure for ordinal data and is fairly straight forward when there are no ties in ... [Read more...]

Spearman’s Rho Rank Correlation There are generally three types of correlation that a researcher may encounter: Pearson’s r, Kendall’s Tau, and Spearman’s Rho.  They each have their own uses and applications depending on the da... [Read more...]

The last Le Monde puzzle made me wonder about the ternary version of the sorting algorithms, which all seem to be binary (compare x and y, then…). The problem is, given (only) a blackbox procedure that returns the relative order of three arbitrary numbers, how many steps are necessary to ... [Read more...]

The puzzle of last weekend in Le Monde was about finding the absolute rank of x9 when given the relative ranks of x1,….,x8 and the possibility to ask for relative ranks of three numbers at a time. In R terms, this means being able to use or yet being ... [Read more...]