title: Domain adaptation of statistical machine translation with domain-focused web crawling.
abstract: In this paper, we tackle the problem of domain adaptation of statistical machine translation (SMT) by exploiting domain-specific data acquired by domain-focused crawling of text from the World Wide Web. We design and empirically evaluate a procedure for automatic acquisition of monolingual and parallel text and their exploitation for system training, tuning, and testing in a phrase-based SMT framework. We present a strategy for using such resources depending on their availability and quantity supported by results of a large-scale evaluation carried out for the domains of environment and labour legislation, two language pairs (English-French and English-Greek) and in both directions: into and from English. In general, machine translation systems trained and tuned on a general domain perform poorly on specific domains and we show that such systems can be adapted successfully by retuning model parameters using small amounts of parallel in-domain data, and may be further improved by using additional monolingual and parallel training data for adaptation of language and translation models. The average observed improvement in BLEU achieved is substantial at 15.30 points absolute.
authors.affiliation: Charles University in Prague, Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Pecina
authors.affiliation: Dublin City University, Dublin, Ireland.
authors.forename: Antonio
authors.initials: A
authors.lastname: Toral
authors.affiliation: Institute for Language and Speech Processing/Athena RIC, Athens, Greece.
authors.forename: Vassilis
authors.initials: V
authors.lastname: Papavassiliou
authors.affiliation: Institute for Language and Speech Processing/Athena RIC, Athens, Greece.
authors.forename: Prokopis
authors.initials: P
authors.lastname: Prokopidis
authors.affiliation: Charles University in Prague, Prague, Czech Republic.
authors.forename: Aleš
authors.initials: A
authors.lastname: Tamchyna
authors.affiliation: Dublin City University, Dublin, Ireland.
authors.forename: Andy
authors.initials: A
authors.lastname: Way
authors.affiliation: Universität des Saarlandes, 66123 Saarbrücken, Germany ; DFKI, German Research Center for Artificial Intelligence, 66123 Saarbrücken, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: van Genabith
keywords: Domain adaptation ; Optimisation; Statistical machine translation; Web crawling