Issues In Synchronizing The English Treebank And PropBank

The PropBank primarily adds semantic role labels to the syntactic constituents in the parsed trees of the Treebank. The goal is for automatic semantic role labeling to be able to use the domain of locality of a predicate in order to find its arguments. In principle, this is exactly what is wanted, but in practice the PropBank annotators often make choices that do not actually conform to the Treebank parses. As a result, the syntactic features extracted by automatic semantic role labeling systems are often inconsistent and contradictory. This paper discusses in detail the types of mismatches between the syntactic bracketing and the semantic role labeling that can be found, and our plans for reconciling them.