Knowledge Sources for Constituent Parsing of German, a Morphologically Rich and Less-Configurational Language

Alexander Fraser
Helmut Schmid
Richard Farkas
Renjing Wang
Hinrich Schuetze

We study constituent parsing of German, a morphologically rich and
less-configurational language.  We use a PCFG treebank grammar that
has been adapted to the morphologically rich properties of German by
markovization and special features added to its productions. We
evaluate the impact of adding lexical knowledge.  Then we examine both
monolingual and bilingual approaches to parse reranking. Our reranking
parser is the new state of the art in constituency parsing of the
Tiger treebank.  We perform an analysis, concluding with lessons
learned which apply to parsing other morphologically rich and
less-configurational languages.