What normalization technique does RankProd use

Question

[subhash.2204]

Hi... I'm very new to RankProduct package of R... I was trying to run some sample code, but I dont understand where exactly the normalization of data happens here...? Is there any specific technique that RankProd uses?

Answer 1

[Lars Juhl Jensen]

The short answer is that RankProd does not normalize or require normalization of the data. It is a non-parametric rank-based method, which means that it only looks at the order of the genes on the lists, not at their actual expression values (Hong et al., 2006). It is thus invariant to any positive monotonic transformation of the expression values, since such transformations do not change the order.