On the Use of Median String for Multi-source Translation

State-of-the-art approaches to multi-source translation involve a multimodal-like process which applies an individual translation system to each source language. Then, the translations of the individual systems are combined to obtain a consensus output. We propose to use the (generalised) median string as the consensus output of the individual translation systems. Different approximations to the median string are studied as well as different approaches to improve the median string performance when dealing with natural language strings. The proposed approaches were evaluated on the Europarl corpus, achieving significant improvements in translation quality.