Thread:User talk:LArron/You're good at statistics

Is there any way to "measure" the accuracy of a prediction of a ranking of items? I ask because I'm interested in this claim by Andy. Presumably, it's not just about position ("Rick Santorum is the only item, of ten, that retained position, therefore the prediction was 10% accurate"), but also about the order - the relative positions of the items in the prediction and the result.