Finite Structure Query: A Tool for Querying Syntactically Annotated Corpora

Finite Structure Query: A Tool for Querying Syntactically Annotated Corpora Stephan Kepser SFB 441 — University of Tubingen Nauklerstr. 35, 72074 Tubingen, Germany kepser@sfs.uni-tuebingen.de Abstract Finite structure query (fsq for short) is a tool for querying syntactically anno- tated corpora. fsq employs a query lan- guage of high expressive power, namely full first order logic. It can be used to query arbitrary finite structures, not just trees. 1 Introduction In recent years large amounts of electronic texts have become available providing a new base for empirical studies in linguistics and offering a chance to linguists to compare their theories with large amounts of utterances from "the real world". While tagging with morphosyntactic categories has become a standard for almost all corpora, more and more of them are nowadays annotated with refined syntactic information. Examples are the Penn Treebank (Marcus et al., 1993) for American English annotated at the University of Pennsylvania, the French treebank (AbelIle and Clement, 1999) developed in Paris, the NEGRA Corpus (Brants et al., 1999) for German anno- tated at the University of Saarbriicken, and the Tubingen Treebanks (Hinrichs et al., 2000) for Japanese, German and English from the Univer- sity of Tithingen. To make these rich syntactic an- notations accessible for linguists the development of powerful query tools is an obvious need and has become an important task in computational linguistics. In this paper, we present finite structure query (fsq), a query tool for syntactically annotated cor- pora. Special emphasis in the development of fsq is layed on providing users a very powerful query language. Therefore full first-order logic was chosen as query language which allows ar- bitrary quantifications over nodes in a tree. This choice is to the authors' knowledge unique, no other query tool offers such an expressive power. It is on the other hand not arbitrary, we will show that there are interesting linguistic queries that re- quire such an expressive power. The tool is de- veloped for treebanks in NEGRA export format (Brants, 1997), but can be adopted to other cor- pus formats as well. The linguistic examples that follow are from the Tubingen Treebanks 1.1 The Tiibingen Treebanks The Tiibingen Treebanks, annotated at the Uni- versity of Tiibingen, comprise a German, an En- glish and a Japanese treebank consisting of spo- ken dialogs restricted to the domain of arranging business appointments. In this paper, we focus on the German treebank (TiiBa-D) (Stegmann et al., 2000; Hinrichs et al., 2000) that contains approx- imately 38.000 trees. The treebank is part-of-speech tagged using the Stuttgart-TUbingen tag set (STTS) developed by Schiller et al. (1995). One of the design deci- sions for the development of the treebank was the commitment to reusability. As a consequence, the choice of the syntactic annotation scheme should not reflect a particular syntactic theory but rather be as theory-neutral as possible. There- fore a surface-oriented scheme was adopted to structure German sentences that uses the notion of topological fields in a sense similar to that of Mile (1985). The …

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