This is kind of like how the value of information is how surprising it is. Classic information theory, but with a twist, because in these cases the "surprise" e

This is kind of like how the value of information is how surprising it is. Classic information theory, but with a twist, because in these cases the "surprise" element is often not the value of the information itself, but the way it is presented. So these algorithms are quite good at recognizing when things are surprising and thus perhaps deserving of wider sharing, but bad at recognizing what kind of surprise it is - is it actually new information, or is it just froth?