What algorithm does Google use for it's adsense program?

To match ads with relevant websites

[tomld2]

Hi folks, I am just wondering what algorithm or process Google uses to match text ads with relevant websites in it adsense program? For example how would it know to not show an ad relating to java coding, for a coffee website?

Can anyone briefly explain or point me toward a resource that details the algorithm Google uses to match it's Adsense ads with relevant websites?

Regards,
Tom

[blasto333]

Google's algorithm is proprietary.

[danny]

My page for reviews of books about Java reliably gets ads for hotels in Java, so Google's algorithm seems to have no problems there. I'd guess the presence of the word "Indonesia" is the biggest clue.

There used to be an island between Sumatra and Bali, but Sun Microsystems has swept it off the Net.

[brotherhood of LAN]

Like Danny's example, tom you might want to try having a look for "applied semantics" or "applied semantics white paper".

In the paper they mention stemming the form of words as well as looking at the sense of words i.e. java

[tomld2]

Is there an algorithm available that can be purchased, that would serve relevant ads based on a pages content? What I am trying to do is serve text links through an ad network, but instead factor in the entire pages content instead of a single individual keyword. Again, Java is a classic example...

Regards,
Tom