NEGRA

The paper aims at a deeper understanding of sev- eral well-known algorithms and proposes ways to optimize them. It describes and discusses factors and strategies of factor interaction used in …...

In this paper, we present an unlexical- ized parser for German which employs smoothing and suffix analysis to achieve a labelled bracket F-score of 76.2, higher than previously reported results …...

We investigate generalizations of the all- subtrees "DOP" approach to unsupervised parsing. Unsupervised DOP models assign all possible binary trees to a set of sentences and next use (a large …...

This paper presents a comparative study of probabilistic treebank parsing of Ger- man, using the Negra and T¨uBa-D/Z tree- banks. Experiments with the Stanford parser, which uses a factored PCFG …...

We propose a generalization of the super- vised DOP model to unsupervised learning. This new model, which we call U-DOP, initially assigns all possible unlabeled binary trees to a set …...

The average results obtained by unsupervised statistical parsers have greatly improved in the last few years, but on many specific sentences they are of rather low quality. The output of …...

AbstractWe introduce a novel chart-based algorithm for span-based parsing of discontinuous constituency trees of block degree two, including ill-nested structures. In particular, we show that we can build variants of …...