Thai poetry translation to English with backward translation evaluation

The Poetry is an art form of literary works. Poetry Machine Translator is problematic area challenging. It is very important that output of poetry translation should still be poetry. Evaluation of translation will show the quality of translator but Evaluation is still a research topic in itself. This paper will focus on the Thai poetry type “Klonn-Pad” and aim to translate into English keeping terms of prosody. The results of translation between Forward and Backward translation will be compared by BLEU (Bilingual Evaluation Understudy) metric and METEOR (Metric for Evaluation of Translation with Explicit Ordering). The original (Thai) language L1translates to the target language L2. The result of Forward L1to L2 is L2out and the result of Backward L2 to L1 is L1out. The BLEU score of Forward (L2out) equaled 0.795, Backward (L1out) equaled 0.885. The METEOR score of Forward (L2out) Precision equaled 0.863, Recall equaled 0.791 and F-Measure equaled 0.840. For Backward (L1out) Precision equaled 0.850, Recall equaled 0.863 and F-Measure equaled 0.856. Based on this study, it can be concluded that the Backward Translation can validate and evaluate quality the Thai poetry machine translators with Poetry´s dictionary and Tuning Module. Thus, it is necessary and reasonable that Dictionary of Thai poetry should be develop and improve.