A hybrid approach to query and document translation using a pivot language for cross-language information retrieval

This paper reports experimental results for cross-language information retrieval (CLIR) from German to French, in which a hybrid approach to query and document translation was attempted, i.e., combining the results of query translation (German to French) and of document translation (French to German). In order to reduce the complexity of computation when translating a large amount of texts, we performed pseudo-translation, i.e., a simple replacement of terms by a bilingual dictionary (for query translation, a machine translation system was used). In particular, since English was used as an intermediary language for both translation directions between German and French, English translations at the middle stage were employed as document representations in order to reduce the number of translation steps. By omitting a translation step (English to German), the performance was improved. Unfortunately, our hybrid approach did not show better performance than a simple query translation. This may be due to the low performance of document translation, which was carried out by a simple replacement of terms using a bilingual dictionary with no term disambiguation.