General Terms

In this paper, we present MonoTrans2, a new user interface to support monolingual translation; that is, translation by people who speak only the source or target language, but not both. Compared to previous systems, MonoTrans2 supports multiple edits in parallel, and shorter tasks with less translation context. In an experiment translating children's books, we show that MonoTrans2 is able to substantially close the gap between machine translation and human bilingual translations. The percentage of sentences rated 5 out of 5 for fluency and adequacy by both bilingual evaluators in our study increased from 10 % for Google Translate output to 68 % for MonoTrans2. Author Keywords Monolingual, translation, translation interface, human computation, distributed human computation, wisdom of crowds, crowd-sourcing, machine translation