Estimating accuracy of an automatic language translation

A computer system and method for natural language translation uses a translation process to translate a source natural language segment (e.g. English) of one or more source words/elements into a target natural language (e.g. German) segment of one or more target words/elements. An evaluation module determines a confidence measure of the natural language translation, which indicates less confidence as the complexity of the translation increases. The translation process can be terminated if the confidence measure fails to meet a threshold criterion. The translation may involve parsing a segment into a parse structure which is converted via a transfer structure into a target structure, and the complexity of each of these stages may be used to determine the total complexity of the translation.