1. A method of training a machine translation system to generate confidence scores indicative of a quality of a translation result, comprising: translating a source string with a machine translator to generate a target string; extracting features from the machine translator, indicative of performance of translation steps in the machine translator; obtaining a trusted entity-assigned translation score indicative of a trusted entity-assigned translation quality of the target string; and identifying a relationship between a subset of the extracted features and the trusted entity-assigned translation score.