Why Predicting Post-Edition is so Hard? Failure Analysis of LIMSI Submission to the APE Shared Task

This paper describes the two systems submitted by LIMSI to the WMT’15 Shared Task on Automatic Post-Editing. The first one relies on a reformulation of the APE task as a Machine Translation task; the second implements a simple rule-based approach. Neither of these two systems manage to improve the automatic translation. We show, by carefully analyzing the failure of our systems that this counterperformance mainly results from the inconsistency in the annotations.