10. 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; for any subordinating nodes, the percolation circuit assigns the relevance scores of the subordinated discourse constituent to the subordinating discourse constituent if the subordinated discourse constituent is more relevant; and for any coordination nodes, the percolation circuit assigns the relevance score of the most relevant child to other child discourse constituent nodes.
10. 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; for any subordinating nodes, the percolation circuit assigns the relevance scores of the subordinated discourse constituent to the subordinating discourse constituent if the subordinated discourse constituent is more relevant; and for any coordination nodes, the percolation circuit assigns the relevance score of the most relevant child to other child discourse constituent nodes. 11. The system of claim 10 , wherein the structural representation of discourse is determined based on a theory of discourse analysis.