Interactively Exploring a Machine Translation Model 
 
 This paper describes a method of interactively visualizing and directing the process of translating a sentence . The method allows a user to explore a model of syntax-based statistical machine translation (MT) , to understand the model 's strengths and weaknesses, and to compare it to other MT systems . Using this visualization method , we can find and address conceptual and practical problems in an MT system . In our demonstration at ACL , new users of our tool will drive a syntax-based decoder for themselves. 