The World Wide Web constitutes the largest existing source of texts written in a great variety of languages. A feasible and sound way of exploiting this data for linguistic research is to compile a static corpus for a given language. There are several adavantages of this approach: (i) Working with such corpora obviates the problems encountered when using Internet search engines in quantitative linguistic research (such as non-transparent ranking algorithms). (ii) Creating a corpus from web data is virtually free. (iii) The size of corpora compiled from the WWW may exceed by several orders of magnitudes the size of language resources offered elsewhere. (iv) The data is locally available to the user, and it can be linguistically post-processed and queried with the tools preferred by her/him. This book addresses the main practical tasks in the creation of web corpora up to giga-token size. Among these tasks are the sampling process (i.e., web crawling) and the usual cleanups including boilerplate removal and removal of duplicated content. Linguistic processing and problems with linguistic processing coming from the different kinds of noise in web corpora are also covered. Finally, the authors show how web corpora can be evaluated and compared to other corpora (such as traditionally compiled corpora).
Table of Contents
Corpus Evaluation and Comparison
About the Author(s)Roland Schafer
, Freie Universitat Berlin
Roland Schafer studied Theoretical and Indo-European Linguistics as well as Japanese Linguistics at Marburg and Bochum Universities. He completed his doctorate Arguments and Adjuncts at the Syntax-Semantics Interface in 2008 at Gottingen University, supervised by Gert Webelhuth and Regine Eckardt. Since then, he has been working as a research assistant at Freie Universitat Berlin, mainly doing corpus-based research on semantic and morpho-syntactic phenomena. In 2011, he started working on the COW ("Corpora from the Web") project with Felix Bildhauer. His teaching experience covers a wide range of topics including Theoretical and Corpus Linguistics, English and German Linguistics, as well as Computational Linguistics.Felix Bildhauer
, Freie Universitat Berlin
Felix Bildhauer studied Romance Linguistics at the Universities of Gottingen and Barcelona. He received his doctorate from the University of Bremen in 2008 with a dissertation on representing information structure in a Head-Driven Phrase Structure Grammar of Spanish. Since 2007, he has been working as a research assistant at Freie UniversitÃ¤t Berlin, focusing on corpus-based approaches to information structure in German and various Romance languages. With Roland Schafer, he started compiling corpora from the Web to overcome the lack of large, available corpora in some of the languages they are working on. He has taught courses on a variety of subjects, including syntax, phonology, semantics, Corpus Linguistics, and Computational Linguistics.