Anaphoric annotation and corpus-based anaphora resolution: An experiment

Abstract

The paper describes the noun phase and anaphora annotation in OpenCorpora and compares it to that in other corpora. We discuss the choice of representa- tive texts for anaphoric annotation and the basic principles of syntactic anno- tation. In case of noun phrase annotation we followed the scheme introduced earlier for morphological annotation: it was carried out in two stages: rstly, all noun phrases and some other syntactic units were annotated by a heterog- enous group of people, then a linguist compared all markup results and found the best one, or corrected mistakes. We present some annotation results and cases of annotator’s disagreement and proceed to introduce our data-driven anaphora resolution system based on decision trees. We then list the features used to t the classi cator and discuss their relevance and some changes which improved the classi cator performance. We also present out rule-based approach to automated noun phrase extraction using Tomita parser. A baseline for anaphora resolution is introduced and we compare it with our results.