Enhancing PTB Universal Dependencies for Grammar-Based Surface Realization

Grammar-based surface realizers require inputs compatible with their reversible, constraint-based grammars, including a proper representation of unbounded dependencies and coordination. In this paper, we report on progress towards creating realizer inputs along the lines of those used in the first surface realization shared task that satisfy this requirement. To do so, we augment the Universal Dependencies that result from running the Stanford Dependency Converter on the Penn Treebank with the unbounded and coordination dependencies in the CCGbank, since only the latter takes the Penn Treebank’s trace information into account. An evaluation against gold standard dependencies shows that the enhanced dependencies have greatly enhanced recall with moderate precision. We conclude with a discussion of the implications of the work for a second realization shared task.