Patent ID: 7870141

Claim:
A method for finding a focus of a document using a semantic network comprising a plurality of nodes, each node representing a concept, and links, connecting the nodes, each link representing relations between the concepts, comprising: providing a list of terms found in an input document which match concepts represented by the semantic network, as well as a frequency value for each matched term indicating a number of times the term appears in the input document; mapping each matched term to a referent node or to a plurality of possible referent nodes in the semantic network; assigning weights to nodes, comprising: for each matched term: i) selecting one of the referent nodes as a start node; ii) assigning the start node an initial weight depending on the frequency value of the term; iii) carrying out a depth-first traversal of the semantic network from the start node, at each node in the traversal calculating a weight of the current node based on the weight of the previous node in the traversal and a stepping factor, the search backtracking to the previous nodes when the weight of a current node is found to be less than a predefined weight threshold; and iv) repeating i) to iii) for a next referent node for the term; and repeating i) to iv) for the next matched term; and adding together the weights for each node from all traversals; and determining a focus of the input document based on the assigned weights of the nodes.