Relational Evaluation Schemes

We describe extensions to a scheme for evaluating parse selection accuracy based on named grammatical relations between lemmatised lexical heads. The scheme is intended to directly reflect the task of recovering grammatical and logical relations, rather than more arbitrary details of tree topology. There is a manually annotated test suite of 500 sentences which has been used by several groups to perform evaluations. We are developing software to create larger test suites automatically from existing treebanks. We are considering alternative relational annotations which draw a clearer distinction between grammatical and logical relations in order to overcome limitations of the current proposal.