Pavel Straňák

The CoNLL-2009 Shared Task: Syntactic and Semantic Dependencies in Multiple Languages

For the 11th straight year, the Conference on Computational Natural Language Learning has been accompanied by a shared task whose purpose is to promote natural language processing applications and evaluate them in a standard setting. In 2009, the shared task was dedicated to the joint parsing of syntactic and semantic dependencies in multiple languages. This shared task combines the shared tasks of the previous five years under a unique dependency-based formalism similar to the 2008 task. In this paper, we define the shared task, describe how the data sets were created and show their quantitative properties, report the results and summarize the approaches of the participating systems.

Influence of treebank design on representation of multiword expressions

Multiword Expressions (MWEs) are important linguistic units that require special treatment in many NLP applications. It is thus desirable to be able to recognize them automatically. Semantically annotated corpora should mark MWEs in a clear way that facilitates development of automatic recognition tools. In the present paper we discuss various corpus design decisions from this perspective. We propose guidelines that should lead to MWE-friendly annotation and evaluate them on numerous sentence examples. Our experience of identifying MWEs in the Prague Dependency Treebank provides the base for the discussion and examples from other languages are added whenever appropriate.

The lexico-semantic annotation of PDT: some results, problems and solutions

This paper presents our experience with the lexico-semantic annotation of the Prague Dependency Treebank (PDT) We have used the Czech WordNet (CWN) as an annotation lexicon (repository of lexical meanings) and we annotate each word which is included in the CWN Based on the error analysis we have performed some experiments with modification of the annotation lexicon (CWN) and consequent re-annotation of occurrences of selected lemmas We present the results of the annotations and improvements achieved by our corrections.