While domain adaptation techniques for SMT have proven to be effective at improving translation quality, their practicality for a multi-domain environment is often limited because of the computational and human costs of developing and maintaining multiple systems adapted to different domains. We present an architecture that delays the computation of translation model features until decoding, allowing for the application of mixture-modeling techniques at decoding time. We also describe a method for unsupervised adaptation with development and test data from multiple domains. Experimental results on two language pairs demonstrate the effectiveness of both our translation model architecture and automatic clustering, with gains of up to 1 BLEU over unadapted systems and single-domain adaptation.
['Rico Sennrich', 'Holger Schwenk', 'Walid Aransa']
A Multi-Domain Translation Model Framework for Statistical Machine Translation