My impression is that PageRank, while initially extremely successful at filtering signal-from-noise, is very susceptible to manipulation. For example links farms which make unimportant pages seem important. As a result of such manipulation, Google started modifying their crawling, in order to reduce the amount of garbage going into PageRank (less garbage in, less garbage out). For example, they might look at the age and ownership in DNS records, and exclude domains that look fishy based on some heuristics. The spammers fought back with more tricks, and the resulting arms race has come to have an acronym: SEO. But the underlying idea of using an iterative approximation of the likelihood of encountering a page via a random walk of the web is preserved. (Some details here: http://www.miislita.com/information-retrieval-tutorial/matri...)
If that's right (and I could well be wrong... would like to be convinced...), then I don't see it as a "light-years away" kind of issue, but rather a series of hacks to stay one step ahead of the spammers. I don't see any particular value in open sourcing those.
My impression is that PageRank, while initially extremely successful at filtering signal-from-noise, is very susceptible to manipulation. For example links farms which make unimportant pages seem important. As a result of such manipulation, Google started modifying their crawling, in order to reduce the amount of garbage going into PageRank (less garbage in, less garbage out). For example, they might look at the age and ownership in DNS records, and exclude domains that look fishy based on some heuristics. The spammers fought back with more tricks, and the resulting arms race has come to have an acronym: SEO. But the underlying idea of using an iterative approximation of the likelihood of encountering a page via a random walk of the web is preserved. (Some details here: http://www.miislita.com/information-retrieval-tutorial/matri...)
If that's right (and I could well be wrong... would like to be convinced...), then I don't see it as a "light-years away" kind of issue, but rather a series of hacks to stay one step ahead of the spammers. I don't see any particular value in open sourcing those.