Rank correlations [30] are correlations in connection with ordinal data. Here I will describe 2 rank correlations which both are particular cases of the general correlation coefficient. The data ranks should here be described by integers from one to the number of elements.
The following example is from [30]:
Here are 10 boys abilities in mathematics and music put in 2 ordinal rankings. A rank correlation should tell if a boy being bright in mathematics is likely to be musical compared to the other 9.
