Our approach follows Langkilde-Geary (2002) and Callaway (2003) in aiming to leverage the Penn Treebank to develop a broad-coverage surface realizer for English.
while these earlier, generation-only approaches made use of converters for transforming the outputs of Treebank parsers to inputs for realization, our approach instead employs a shared bidirectional grammar, so that the input to realization is guaranteed to be the same logical form constructed by the parser.