This paper presents a detailed study of a method for morphology generalization and generation to address out-of-domain translations in English-to-Spanish phrase-based MT. The paper studies whether the morphological richness of the target language causes poor quality translation when translating out-of-domain. In detail, this approach first translates into Spanish simplified forms and then predicts the final inflected forms through a morphology generation step based on shallow and deep-projected linguistic information available from both the source and target-language sentences. Obtained results highlight the importance of generalization, and therefore generation, for dealing with out-of-domain data.

Content localisation via machine translation (MT) is a sine qua non, especially for international online business. While most applications utilise rule-based solutions due to the lack of suitable in-domain parallel corpora for statistical MT (SMT) training, in this paper we investigate the possibility of applying SMT where huge amounts of monolingual content only are available. We describe a case study where an analysis of a very large amount of monolingual online trading data from eBay is conducted by ALS with a view to reducing this corpus to the most representative sample in order to ensure the widest possible coverage of the total data set. Furthermore, minimal yet optimal sets of sentences/words/terms are selected for generation of initial translation units for future SMT system-building.

String comparison methods such as BLEU (Papineni et al., 2002) are the de facto standard in MT evaluation (MTE) and in MT system parameter tuning (Och, 2003). It is difficult for these metrics to recognize legitimate lexical and grammatical paraphrases, which is important for MT system tuning (Madnani, 2010). We present two methods to address this: a shallow lexical substitution technique and a grammar-driven paraphrasing technique. Grammatically precise paraphrasing is novel in the context of MTE, and demonstrating its usefulness is a key contribution of this paper. We use these techniques to paraphrase a single reference, which, when used for parameter tuning, leads to superior translation performance over baselines that use only human-authored references.

We have developed a two-stage machine translation (MT) system. The first stage consists of an automatically created pattern-based machine translation system (PBMT), and the second stage consists of a standard phrase-based statistical machine translation (SMT) system. We studied for the Japanese-English simple sentence task. First, we obtained English sentences from Japanese sentences using an automatically created Japanese-English pattern-based machine translation. We call the English sentences obtained in this way as “English”. Second, we applied a standard SMT (Moses) to the results. This means that we translated the “English” sentences into English by SMT. We also conducted ABX tests (Clark, 1982) to compare the outputs by the standard SMT (Moses) with those by the proposed system for 100 sentences. The experimental results indicated that 30 sentences output by the proposed system were evaluated as being better than those outputs by the standard SMT system, whereas 9 sentences output by the standard SMT system were thought to be better than those outputs by the proposed system. This means that our proposed system functioned effectively in the Japanese-English simple sentence task.

This paper presents a method to improve a word alignment model in a phrase-based Statistical Machine Translation system for a low-resourced language using a string similarity approach. Our method captures similar words that can be seen as semi-monolingual across languages, such as numbers, named entities, and adapted/loan words. We use several string similarity metrics to measure the monolinguality of the words, such as Longest Common Subsequence Ratio (LCSR), Minimum Edit Distance Ratio (MEDR), and we also use a modified BLEU Score (modBLEU). Our approach is to add intersecting alignment points for word pairs that are orthographically similar, before applying a word alignment heuristic, to generate a better word alignment. We demonstrate this approach on Indonesian-to-English translation task, where the languages share many similar words that are poorly aligned given a limited training data. This approach gives a statistically significant improvement by up to 0.66 in terms of BLEU score.

The performance of an SMT system heavily depends on the availability of large parallel corpora. Unavailability of these resources in the required amount for many language pair is a challenging issue. The required size of the resource involving morphologically rich and highly agglutinative language is essentially much more for the SMT systems. This paper investigates on some of the issues on enriching the resource for this kind of languages. Handling of inflectional and derivational morphemes of the morphologically rich target language plays important role in the enrichment process. Mapping from the source to the target side is carried out for the English-Manipuri SMT task using factored model. The SMT system developed shows improvement in the performance both in terms of the automatic scoring and subjective evaluation over the baseline system.

We aim to use statistical machine translation technology to correct grammar errors and style issues in monolingual text. Here, as a feasibility test, we focus on depassivization in German and we abstract from surface forms to parts of speech. Our results are not yet satisfactory but yield useful insights into directions for improvement.