Evaluating a German Sketch Grammar: A Case Study on Noun Phrase Case

Word sketches are part of the Sketch Engine corpus query system. They represent automatic, corpus-derived summaries of the words' grammatical and collocational behaviour. Besides the corpus itself, word sketches require a sketch grammar, a regular expression-based shallow grammar over the part-of-speech tags, to extract evidence for the properties of the targeted words from the corpus. The paper presents a sketch grammar for German, a language which is not strictly configurational and which shows a considerable amount of case syncretism, and evaluates its accuracy, which has not been done for other sketch grammars. The evaluation focuses on NP case as a crucial part of the German grammar. We present various versions of NP definitions, so demonstrating the influence of grammar detail on precision and recall.

• Type: Conference
• Year: 2008
• Where: LREC
• Authors: Kremena Ivanova, Ulrich Heid, Sabine Schulte im Walde, Adam Kilgarriff, Jan Pomikálek
• Keywords: Education, LREC 2008, Sketch Engine Corpus, Sketch Grammars, Word Sketches