  While dependency parsers reach very high overall accuracy, some dependency
relations are much harder than others. In particular, dependency parsers
perform poorly in coordination construction (i.e., correctly attaching the
"conj" relation). We extend a state-of-the-art dependency parser with
conjunction-specific features, focusing on the similarity between the conjuncts
head words. Training the extended parser yields an improvement in "conj"
attachment as well as in overall dependency parsing accuracy on the Stanford
dependency conversion of the Penn TreeBank.
