1 Accordingly, it is not possible to draw a straightforward quantitative comparison between our PropBank SSN parser and other PropBank parsers.
state-of-theart semantic role labelling systems (CoNLL, 2005) use parse trees output by state-of-the-art parsers (Collins, 1999;Charniak, 2000), both for training and testing, and return partial trees annotated with semantic role labels.