1 Overview
The Kendall (1955) rank correlation coefficient evaluates the degree
of similarity between two sets of ranks given to a same set of
objects. This coefficient depends upon the number of inversions
of pairs of objects which would be needed to transform one rank
order into the other. In order to do so, each rank order is represented
by the set of all pairs of objects (e.g., [a,b] and [b,a] are the
two pairs representing the objects a and b), and a value of 1 or
0 is assigned to this pair when its order corresponds or does not
correspond to the way these two objects were ordered. This coding
schema provides a set of binary values which are then used to
compute a Pearson correlation coefficient.