17. A system for determining hybrid text summaries comprising: an input/output circuit for retrieving a text; a processor for determining discourse constituents for the text and attaching the discourse constituents into a structural representation of discourse; a relevance score determination circuit for determining relevance scores for the discourse constituents based on at least one non-structural measure of relevance; and a percolation circuit for percolating discourse constituent relevance scores based on the structural representation of discourse and where the processor determines a hybrid text summary based on the discourse constituents with relevance scores exceeding a threshold relevance score, wherein for each child discourse constituent node in the structural representation, the percolation circuit assigns the relevance score of the child discourse constituent node to the parent discourse constituent node if the child discourse constituent node is more relevant than its parent; for each coordinated discourse constituent node, the percolation circuit assigns the relevance score of the coordinated discourse constituent node to each preceding less relevant sibling node; for each child discourse constituent node that is not a coordinated discourse constituent node and is not a subordinated discourse constituent node, the percolation circuit assigns the relevance score of the parent discourse constituent node to the child discourse constituent node if the parent discourse constituent is more relevant than the child; for each coordinated discourse constituent node, the percolation circuit assigns the relevance score of the parent discourse constituent node to the coordinated discourse constituent node, if the coordinated discourse node and all its siblings are less relevant than the parent node; for each subordinated discourse constituent node, the percolation circuit assigns the relevance score of the subordinated discourse constituent node to the subordinating discourse constituent if the subordinated discourse constituent is more relevant than the subordinating node; and for each node, repeating these steps, until the percolation circuit can find no node whose relevance score is changed to the relevance score of another node.
17. A system for determining hybrid text summaries comprising: an input/output circuit for retrieving a text; a processor for determining discourse constituents for the text and attaching the discourse constituents into a structural representation of discourse; a relevance score determination circuit for determining relevance scores for the discourse constituents based on at least one non-structural measure of relevance; and a percolation circuit for percolating discourse constituent relevance scores based on the structural representation of discourse and where the processor determines a hybrid text summary based on the discourse constituents with relevance scores exceeding a threshold relevance score, wherein for each child discourse constituent node in the structural representation, the percolation circuit assigns the relevance score of the child discourse constituent node to the parent discourse constituent node if the child discourse constituent node is more relevant than its parent; for each coordinated discourse constituent node, the percolation circuit assigns the relevance score of the coordinated discourse constituent node to each preceding less relevant sibling node; for each child discourse constituent node that is not a coordinated discourse constituent node and is not a subordinated discourse constituent node, the percolation circuit assigns the relevance score of the parent discourse constituent node to the child discourse constituent node if the parent discourse constituent is more relevant than the child; for each coordinated discourse constituent node, the percolation circuit assigns the relevance score of the parent discourse constituent node to the coordinated discourse constituent node, if the coordinated discourse node and all its siblings are less relevant than the parent node; for each subordinated discourse constituent node, the percolation circuit assigns the relevance score of the subordinated discourse constituent node to the subordinating discourse constituent if the subordinated discourse constituent is more relevant than the subordinating node; and for each node, repeating these steps, until the percolation circuit can find no node whose relevance score is changed to the relevance score of another node. 18. The system of claim 17 , wherein the percolation is applied to progressively larger sets of linked nodes.