Semantic Dependency Relations

(This is a copy of my blog post mode on the wordpress opencog brainwave blog on 5th of October 2009 -- Linas Vepstas.)

I spent the weekend comparing the Stanford parser to RelEx, and learned a lot. RelEx really does deserve to be called a “semantic relation extractor”, and not just a “dependency relation extractor”. It provides a more abstract, more semantic output than the Stanford parser, which sticks very narrowly to the syntactic structure of a sentence.

I wrote up a few paragraphs on the most prominent differences; most of my updates were to the RelEx dependency relations page.

Here are the main bullet points:

Its also clear to me that I could split up the relex processing into two stages: one which generates stanford-style syntactic relations, and a second stage that generates the more abstract stuff. This might be a wise move … Since RelEx is already more than 3x faster than the Stanford parser, this could attract new users.