The role of "back translation" in the quality process

The practice known as "back translation" is defined as taking the translated text of a source document and translating it back into the original source language. For a translation from English to German, the German document would then be translated back into English and compared with the original source. Back translations are often requested when individuals are not familiar with the target language and they want to judge the quality of translations.

Back translation is part of the quality control process and can be used in various ways and with various degrees of rigor, depending on the objective. The most common objective is to identify actual or potential trouble spots in the translation as well as in the original text in order to remedy them. There are some situations where this practice is useful but there are also serious drawbacks.

When to use back translation?

It is mostly used for documents in which content integrity is so critical as to justify the extra time and expense of a second round of translation, followed by comparison and remediation. In such documents, which tend to be scientific or legal in nature, translation accuracy and readability have a bearing either on the validity or the outcome of a scientific study, on legal or ethical liability.

Examples of such documents include

medical consent forms, especially for clinical trials

patient instruction material

operations and training manuals

legal and financial reports

opinion surveys

election ballots

Documents with instructions or procedures may also benefit from this process. Back translation can point out places where something was misunderstood. But divergence between the source document and back translation may not necessarily point to a mistranslation.

Issues with back translation

When one or more parties are not aware of the fact that the translation is in fact a back translation, the translator may decipher the intent of the original translation and thus render a fully comprehensible back translation even if the translation from which he or she is working is unintelligible to native speakers of the target language.
In such situations, the translator will write an accurate, meaningful and understandable translation without pointing out the errors such as spelling and grammatical mistakes. In this case, it would be most useful to share specific instructions with the translator about the back translation process. For example, the client can instruct to document all spelling and grammar mistakes, mark the ambiguous areas ...

Another risk may come up when instructions are given and the second translator is aware that it is a back translation but his/her competencies don't match the level of experience and skills in the subject area. He or she may suggest deletions or additions leading to unnecessary exchanges with the original author and translator. It could create additional expenses and delay along with compromising the actual translation.