Document ranking strategy for P2P file sharing system.

Question

Recently, I got a task of building a P2P file sharing system.

There is one requirement : the system should have a document ranking algorithm so that it could be used help users find more valuable files.

Several strategy might be useful :

• force user to give a score to a file before it was downloaded

• The documents containing certain key words would get higher rank

• Manager could modify file ranking manually

• the more a file was downloaded, it would get a higher rank.

Do you know any other strategy or methods that also appropriate? Or is there any real world example?

Answer 1

I would go with a combination of 1 and 4 but without forcing users to give a ranking. However I would give more weight in the algorithm to user rankings rather then downloads, as the downloads only indicate how many times it was downloaded not how useful it was to the user. The problem with forcing a user to give a ranking is that they can't give a ranking before they download the file, since they won't know its contents without having gotten it.

If this is a system that requires users to login, then you could present them with some sort of dialog or something to rate files they have previously downloaded, therefore not forcing anything but giving them the option. If they choose not to rank to a file, then count that as a zero rank or just ignore it depending on your needs.