The CoNLL-2008 shared task on joint parsing of syntactic and semantic dependencies

The Conference on Computational Natural
Language Learning is accompanied every
year by a shared task whose purpose
is to promote natural language processing
applications and evaluate them in a standard
setting. In 2008 the shared task was
dedicated to the joint parsing of syntactic
and semantic dependencies. This shared
task not only unifies the shared tasks of
the previous four years under a unique
dependency-based formalism, but also extends
them significantly: this year’s syntactic
dependencies include more information
such as named-entity boundaries; the
semantic dependencies model roles of both
verbal and nominal predicates. In this paper,
we define the shared task and describe
how the data sets were created. Furthermore,
we report and analyze the results and
describe the approaches of the participating
systems.