Patent ID: 7240055

Claim:
A method for identifying hub experts within a community of users and authoritative documents in a recommender system, comprising: identifying documents in a particular field provided by users within the community; for each identified document: determining which users within the community have acted upon the identified document; determining which of the users who have acted upon the identified document are aware of other relevant documents in the particular field and have not directly produced documents in the particular field; and defining those users as hub experts in the particular field; determining which identified documents have been acted upon by a predetermined number of hub experts; defining those documents as authoritative documents; and associating the hub experts with the authoritative documents; wherein the steps of defining the hub experts and authoritative documents comprise: defining a connectivity matrix M, wherein element M ij is non-zero if and only if there is an arc from node i to node j; wherein for a given node i, a i is an authority value and h i is a hub value, such that: a i = ∑ j ⁢ ⁢ M ji ⁢ h j ⁢ ⁢ ⁢ and ⁢ ⁢ h i = ∑ j ⁢ ⁢ M ij ⁢ a j whose solutions are the principal eigenvectors of M′M_ and MM′, respectively; and defining vectors a=[a 1 , a 2 , . . . a n ]′ and h=[h 1 , h 2 , . . . h n ]′, such that a=M′h=M′Ma, and h=Ma=MM′h wherein node I represents an authoritative document and node j represents a hub expert; and wherein a represents an authority value for an authoritative document and wherein h represents a hub value for a hub expert; generating a list of hub experts associated with the authoritative documents.