## CPS on LETOR4.0

CPS is a new probabilistic model over permutations, which is defined with a coset-permutation distance, and models the generation of a permutation as a stagewise process.

The CPS model has rich expressiveness and can therefore be used in versatile applications, because many different permutation distances can be used to induce the coset-permutation distance. The complexity of the CPS model is low because
of the stagewise decomposition of the permutation probability and the efficient
computation of most coset-permutation distances.

Details can be found at this NIPS 2010 paper
NIPS 2010 paper.

The experiments of BordaCount on LETOR4.0 were conducted by Xiubo Geng. If any problem, please contact letor@microsoft.com.