⭐⭐⭐⭐⭐ Five stars equals excellent work which does not require much editing by the proofreader. Preferential changes can be made, as with any translation. The proofreader can easily see that enough time was spent on the translation to ensure high quality.
⭐⭐⭐⭐Four stars means that the translation was well done. It is free of major inconsistencies or carelessness. Some minor errors may be present if the translation was otherwise carefully done. Your job as a proofreader was relatively easy, but not totally unnecessary.
⭐⭐⭐A three-star translation can be described as solid or acceptable, although the amount of corrections by the proofreader may be substantial. A three-star translation can be improved with reasonable effort into a good text, and you would not consider sending it back to the translator to be re-translated.
⭐⭐ Two stars means disappointing quality. For example, if the sentence structure is taken directly from the source language (often the case with unedited MT) or the job has several errors. As a proofreader you notice that the job was translated hastily and without a final check. TF Support will receive a notification whenever a job receives 1 or 2 stars.
⭐ One star means very poor quality, something the customer is likely to send back to us right away. It means that the translation had severe errors in meaning, grammar, terminology etc. In order to rate a job with one star, there needs to be more than one major error. We always investigate jobs rated with only one star.