in reply to
Re: The (futile?) quest for an automatic paraphrase engine
in thread The (futile?) quest for an automatic paraphrase engine
There seem to be some fairly nice results from statistical methods. I have a couple of references in my post in this thread, but what it boils down to is that there is the knowledge-based way (yours and my preference, apparently) and at least one statistical method being used. The statistical NLP method is called "clustering" because it creates clusters of semantically relevant sentence constituents and then re-uses those constituents to generate a summarization text.