PageRank-Type Algorithm From the 1940s Discovered

KentuckyFC writes "The PageRank algorithm (pdf) behind Google's success was developed by Sergey Brin and Larry Page in 1998. It famously judges a page to be important if it is linked to by other important pages. This circular definition is the basis of an iterative mechanism for ranking pages. Now a paper tracing the history of iterative ranking algorithms describes a number of earlier examples. It discusses the famous HITS algorithm for ranking web pages as hubs and authorities developed by Jon Kleinberg a few years before PageRank. It also discusses various approaches from the 1960s and 70s for ranking individuals and journals based on the importance of those that endorse them. But the real surprise is the discovery of a PageRank-type algorithm for ranking sectors of an economy based on the importance of the sectors that supply them, a technique that was developed by the Harvard economist Wassily Leontief in 1941."

Comments

linearity

[bcrowell]

What really shocked me when someone first described page rank to me was that it was linear. I felt that this just had to be wrong, because it didn't seem right for a *million* inbound links to have a *million* times the effect compared to a single inbound link. Maybe this is just the elitist snob in me, but I don't feel that the latest American Idol singer is really a thousand times better than Billie Holliday, just because a thousand times more people listen to him than to her. If it was me, I'd have used some kind of logarithmic scaling. I think people do usually describe page ranks in terms of their logarithms, but that's taking the log on the final outcome. I'm talking about taking logs at each step before going on to the next iteration.

To me, this has an intuitive connection to the idea that the internet used to be more interesting and quirky, and it was more about individuals expressing themselves, whereas now it's more like another form of TV.

Of course that's not to say that I want to go back to the days before page rank. God, search engine results were just horrible in those days.

From an elitist snob point of view, one good thing about page rank is that it doesn't let you just vote in a passive way, as Nielsen ratings do for TV. In order to have a vote, you have to do something active, like making a web page that links to the page you want to vote for.

Re:Good advice for all developers

[Junior J. Junior III]

"don't reinvent the wheel" is kindof dumb advice when you think about it.

If I didn't already have a wheel, it would take me a really long time to traverse the world in search of a wheel to see if it had been invented yet. If it has, and it's got sufficient penetration into the market that I know about them already, then, sure, it's a no brainer not to reinvent it. On the other hand, if no one in my immediate vicinity has ever heard of the wheel, then inventing one -- quickly -- is a lot smarter than traversing the known world until I run into a culture that already has wheels. Especially if they might exploit their superior technology to subjugate and enslave my people. Better to have a home-brewed shitty wheel to start off with, and upgrade quickly if I discover that there are other friendly cultures that have better wheels already, and have at least something if I don't discover anyone else, or discover hostiles who already have them.

As long as the cart is loosely integrated with the wheels I have, upgrading to better wheels when they are found to be available should be easy. And I might just learn something about wheels while studying them that applies to other problems, or could even possibly improve the existing state of the art with respect to wheels.