hi every body ! recently i got crazy about creating a search engine myself ! i learned about an algorithm, known as "document distance". its very interesting in my view ! if you don't know about it, it's an algorithm that calculates the angel between the vectors of two documents. actually the more different they are in subject, the larger angel they have between. google knows more ! i wonder if anyone knows some basic algorithms like "docDist" that maybe useful in making a search engine. if you got any idea of which kind of knowledge should i gain in order to build a search engine please let me (and maybe others!) know.