Edit Distance: A Metric for Machine Translation Evaluation

AbstractNIST has coordinated machine translation (MT) evaluations for several years using an automatic and repeatable evaluation measure. Under the Global Autonomous Language Exploitation (GALE) program, NIST is tasked with implementing an edit-distance-based evaluation of MT. Here “edit distance” is defined to be the number of modifications a human editor is required to make to a system translation such that the resulting edited translation contains the complete meaning in easily understandable English, as a single high-quality human reference translation. In preparation for this change in evaluation paradigm, NIST conducted two proof-of-concept exercises specifically designed to probe the data space, to answer questions related to editor agreement, and to establish protocols for the formal GALE evaluations. We report here our experimental design, the data used, and our findings for these exercises.