Competences and qualifications of post-editors


Machine translation and post-editing are presenting new challenges for translators. Post-editors juggle three texts that they must keep track of at once: the source text, the MT output and the final target text. To do this, they must keep an eye out for entirely different kinds of errors than those that are expected in human translations. For this reason, the standard ISO 18587 sets high requirements for the professional qualifications of post-editors that build on full translator training.

New challenges for translators

Working with machine translations (MT) is already part of daily life for many translators. Under certain circumstances and upon consultation with the customer, systems for machine translation (MT systems) can be an important aid with which large amounts of text can be processed in a short amount of time while still fulfilling the rising demand for translations. However, automation is fundamentally changing the working methods of translators.

Use of an MT system divides the actual translation process into two steps:

  • the automatic translation of text using a computer application and
  • the post-editing of machine translations by a human translator.

However, these two steps only replace the human translation. The subsequent processes

  • check by the translator (single control principle),
  • revision by another translator (dual control principle),
  • specialist review, etc.

are then performed – as desired by the client – on the post-edited MT output, just like with a human translation.

Two important standards: ISO 17100 and ISO 18587

The standard ISO 17100 on requirements for translation services specifies the competences and qualifications that translators should possess. ISO 18587 on requirements for the post-editing of machine translations takes up precisely the same competences and qualifications. This makes it clear that the post-editor who edits and corrects a machine translation should be a professional translator. In accordance with ISO 18587, however, post-editors must possess additional knowledge and skills to fulfil the professional requirements needed for post-editing.

Competences of post-editors

Both translators and post-editors must possess the following competences:

  • Translation expertise
  • Linguistic and textual competence in the source and target languages
  • Research competence
  • Cultural and technical competence and knowledge of the specialist field

While translators create a new translation from scratch, post-editors must work with a translation that already exists. They should use as much of the MT output as possible so that using the system pays off. However, they must still recognise and correct errors, additions and omissions, edit unsuitable content, ensure the correct and consistent use of terminology, and potentially rephrase sentences to make them idiomatic and appropriate for the target group and intended purpose in the target language.

Qualifications of post-editors

A comparison of the standards mentioned above reveals that translators and post-editors should have the same professional qualifications. Post-editors must therefore also have a relevant degree in the area of translation or several years of full-time work experience as a translator or post-editor.

Professionalism of post-editors

To ensure professionalism in the post-editing processes, ISO 18587 calls for additional knowledge and skills that are required for the post-editing of machine translations. Translators who also work as post-editors must therefore receive appropriate training to develop the following:

  • “a general knowledge of MT technology and a basic understanding of common errors that an MT system makes;
  • a general knowledge of computer-aided translation tools;
  • the knowledge and ability to establish whether editing MT output makes sense, in terms of time and effort estimation;
  • the ability to follow the instructions received and the ability to focus on specific issues and make specific corrections as given.”

Post-editors can provide feedback to the translation service provider or client on recognisable error patterns in the MT output, thus contributing to the improvement of the MT system.

Since post-editing is ideally performed in an integrated translation environment comprising an MT system, a translation memory (TM) system and terminology management, post-editors should also possess general knowledge regarding the interplay between these tools.

Training of post-editors

Texts produced by machine translation systems are not perfect, publication-ready translations. Post-editors must be aware that they will encounter completely different errors than those typically found in a human translation. Neural machine translation systems in particular often produce impressive translations with fluid style, but one should still exercise caution here. Proper names may be translated, abbreviations incorrectly interpreted, information added or left out, specialist terms incorrectly or inconsistently translated, negations unrecognised or false references created.

Post-editors must gain an overview of the weaknesses of the relevant MT system and develop an eye for error patterns. Experience and routine are needed to quickly register which components of the MT output are usable and can be kept and which ones must be rephrased.


MT systems deliver translations at the click of a button. The result might be satisfactory if you only want to gain a rough overview of the content of the source text. But even here you should exercise caution since there is no guarantee for the accuracy of the machine translation. You will have to go one step further, however, if you value technically and terminologically correct texts or if you plan on publishing texts to present your company, products and services in order to gain and keep customers. With post-editing, the MT output is closely inspected and receives the finishing touch. ISO 18587 sets requirements for the competences and qualifications as well as the professionalism of post-editors. Accordingly, post-editors are professional translators with additional qualifications in post-editing.

exact! has been approaching these new challenges head-on and testing various machine translation systems. We are recording and evaluating our experiences from these tests. The translators at exact! are intensely discussing these developments. They are the ones who guarantee that MT output post-edited by exact! speaks our customers’ language – just like our human translations.

If you would like to learn more about requirements for the post-editing of machine translations, also read our blog article “Post-editing in accordance with ISO 18587”.

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