26. The computer program product of claim 16 , wherein the subspace is determined in part by a decomposed term matrix representation of the document collection.
16. A computer program product for summarizing a first unit of text data with relation to an existing document collection, the computer program product including a computer-readable medium encoded with computer program instructions, wherein the computer program instructions, when executed by a processor, cause the processor to perform predetermined operations comprising: computing a term weight that is representative of the relevance of a term to a second unit of text data with relation to the existing document collection; performing one of a domain driven text summarization, an example type query driven text summarization, and a term type query driven text summarization on a selected document; recomposing a vector representation of at least one of the first and second units of text data in a predetermined multidimensional subspace by projecting the vector representation back into an original term space of the existing document collection when performing domain driven text summarization or example type query driven text summarization; computing a relationship of the term to the terms in a query using a term-term matrix associated with the original term space when performing term type query driven text summarization; comparing the computed term weight to a predetermined threshold; and returning a relevant term based at least in part on a result of the comparison.