Arabic-English Transliteration

Out of vocabulary (OOV) words are a common source of errors in cross language information retrieval. Bilingual dictionaries are often limited in their coverage of named- entities, numbers, technical terms and acronyms. There is a need to generate translations for these "on-the-fly" or at query time.

The process of converting a word from one orthography into another is called transliteration.

A significant proportion of OOV words are named entities and technical terms. Typical analyses find around 50% of OOV words to be named entities. Yet these can be the most important words in the queries. Cross language retrieval performance (average precision) reduced more than 50% when named entities in the queries were not translated.

When the query language and the document language share the same alphabet it may be sufficient to use the OOV word as its own translation. However, when the two languages have different alphabets, the query term must somehow be rendered in the orthography of the other language. The process of converting a word from one orthography into another is called transliteration.