Choosing the Best MT Programs for CLIR Purposes – Can MT Metrics Be Helpful?

This paper describes usage of MT metrics in choosing the best candidates for MT-based query translation resources. Our main metrics is METEOR, but we also use NIST and BLEU. Language pair of our evaluation is English *** German, because MT metrics still do not offer very many language pairs for comparison. We evaluated translations of CLEF 2003 topics of four different MT programs with MT metrics and compare the metrics evaluation results to results of CLIR runs. Our results show, that for long topics the correlations between achieved MAPs and MT metrics is high (0.85-0.94), and for short topics lower but still clear (0.63-0.72). Overall it seems that MT metrics can easily distinguish the worst MT programs from the best ones, but smaller differences are not so clearly shown. Some of the intrinsic properties of MT metrics do not also suit for CLIR resource evaluation purposes, because some properties of translation metrics, especially evaluation of word order, are not significant in CLIR.