The goodness of a wordmatch depends on the following factors: (1) level of synonymy -the number of synonyms the words have in common (according to WordNet, Miller et al., 1990); (2) position in sentence; and (3) partof-speech (PoS) -obtained using MINIPAR (Lin, 1998).
a word matches perfectly a word Arg in position in sentence Arg , if both words are exactly the same, they are in the same sentence position, and they have the same PoS.