After obtaining the relative risk levels of the companies, the ranking task can be defined as follows: Given a collection of financial reports D, we aim to rank the companies via a ranking model f : R p → R such that the rank order of the set of companies is specified by the real value that the model f takes.
f (d i ) > f (d j ) means that the model asserts that c i c j , where c i c j means that c i is ranked higher than c j ; that is, the company c i is more risky than c j .