Hacker News new | past | comments | ask | show | jobs | submit login

PageRank doesn't really get "trained" per se, since it's not going to be used to make predictions about other, unseen data.

However, it is learnt from the data: links from one document to another are recorded in a huge adjacency matrix (sort of) and the PageRanks are dominant eigenvector of that matrix.

The original paper never mentions AOL or Yahoo (except as an example of a popular website), but does describe how they built their own crawler (see here: http://ilpubs.stanford.edu:8090/422/1/1999-66.pdf) but I suppose it's possible they got data from those companies later.

It's a kind of unsupervised learning, an intrinsic measure of the network.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact