Annotating topological fields and chunks

Abstract

Annotating a corpus of German with chunks, topological fields and clause boundaries is both a goal in itself and a step towards further syntactic annotation. Partial annotation can serve as data to test linguistic hypotheses and it can be used as a pre-structuring for further linguistic annotation steps. If, however, the underlying part-of-speech (POS) annotation is imperfect, these errors will be passed on to the subsequent levels of annotation and increase annotation errors on those levels. It is especially damaging for subsequent annotation if POS tags are incorrect which provide the framework of the German sentence by demarcating the topological fields and the clause boundaries (e.g. subordinators and verbs). This paper presents a method to automatically annotate a corpus of German with chunks, topological fields and clause boundaries, and improve tagging accuracy at the same time in order to increase the overall annotation accuracy. Tag improvement primarily relies on the linguistic knowledge encoded in the grammar for annotating the topological fields.