A Local Grammar - Dictionary-Graph approach for the extraction of complex text segments

In this talk we will describe a Local Grammar and Dictionary-Graph approach to develop resources for the extraction of complex text segments. A complex text segment is an extended notion of multi-word units (MWUs) that allows a large description of more complex and syntactically more flexible linguistic patterns. First we will present some basics about Unitex/GramLab, an open-source corpus processing suite. Then, we will show how to describe complex language constructions through graphs and how to produce on-the-fly electronic dictionary entries across graphs transductions. As example, we will illustrate a way to combine dictionaries, local grammars and dictionary-graphs to identify some complex text segments as part of an event extraction task. Finally, we will discuss some advantages and drawbacks of our approach and highlight potential perspectives of further research and applications.