The ISPOR Principles of Good Practice paper for the translation of patient-reported outcome (PRO) measures describes concept elaboration within the scope of project preparation and emphasises that the misinterpretation of items or concepts can result if the step is not undertaken. However, the paper does not discuss how to correctly perform concept elaboration or why it is an essential step in the translation process.  Translation companies often harmonise their own translations with each other, but not with existing translations. Over time, a single measure may be translated by any number of companies. Wording choices are often made by various translators and project managers without prior guidance – this can lead to wide variations. A concept elaboration document approved by the developer provides consistent clarification and guidance to promote harmonisation across all language versions regardless of who is carrying out the work. Inconsistent wording choices across language versions can be due to misunderstandings as a result of ambiguous wording in the source text, misinterpretation of idioms or the influence of personal choice resulting in inconsistent use of alternative phrases for terms that are not directly translatable. Concept elaboration remedies these issues by providing a line-by-line analysis of the source text which clarifies ambiguous wording, provides alternative wording for items with no direct translation, recommends suitable equivalents of culture-bound concepts and provides guidelines on nuance, tone, and emphasis. Concept elaboration ensures that the text is fully understood by all translators before any translation work begins. It encourages standardised decision making for every language and allows the developer to exercise influence over the style and content of the translations even if they are unable to review each translation individually. For studies including developer reviews, these reviews should become more straightforward as the translations will have been carried out according to the developer’s guidance.