  Spearman's rank correlation test is commonly used in astronomy to discern
whether a set of two variables are correlated or not. Unlike most other
quantities quoted in astronomical literature, the Spearman's rank correlation
coefficient is generally quoted with no attempt to estimate the errors on its
value. This is a practice that would not be accepted for those other
quantities, as it is often regarded that an estimate of a quantity without an
estimate of its associated uncertainties is meaningless. This manuscript
describes a number of easily implemented, Monte Carlo based methods to estimate
the uncertainty on the Spearman's rank correlation coefficient, or more
precisely to estimate its probability distribution.
