Applying CLP to machine translation: A Greek case study

Abstract

In this research we concentrate on how CSP techniques can contribute to computational linguistics. For this purpose, we tested CP techniques on a linguistic problem of polysemy in machine translation. Ambiguity arises almost every time computers try to deal with human language. In information retrieval, the computer often provides information about alternative meanings of the search terms, meanings that we have no interest in. In machine translation, different meanings of an English word may be expressed by very different words in the target language, so it is important to determine which meaning of the English word the author had in mind and this is where a computer fails. Over and over, attempts to use computers to process human language have been frustrated by the computer’s limited ability to deal with polysemy (Miller 2001). A toy system has been designed for translating between English and Greek. It is based on 6 sentences that, using the same lexicon, can be expanded to slightly more phrases. The translation is based on the results of two parsers — the English and the Greek one. Parsing uses a set of constraints (both semantic and grammatical). The main objective of this research is to evaluate Backtracking as one of CSP algorithms for machine translation. We used PROLOG to write an application because it is the only programming language that supports backtracking and where the choice made by the program can be traced back at every stage.

Keywords

• CLP
• Greek
• ambiguity treatement
• machine translation
• constraint programming
• ProLog