Translation Error Rate

Translation Error Rate (TER) is a metric for automatic evaluation of machine translation that calculates the number of edits required to change a machine translation output into one of the references.

TER is defined as the minimum number of edits needed to change a hypothesis so that it exactly matches one of the references, normalized by the average length of the references.

A Study of Translation Edit Rate with Targeted Human Annotation

TER corresponds to post-editing effort.


  • hTER
  • TERp


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