A human-led assessment of completed translations measured against reference translations or a structured error framework to verify accuracy, fluency, and consistency.
Quality evaluation is a retrospective process. It happens after translation is complete, when a human reviewer (typically a linguist, editor, or subject matter expert) examines the translated content and scores it against a defined set of criteria. The result is an objective, documented assessment of translation quality that informs decisions about whether content is ready to publish, needs revision, or reveals systemic issues with a translation workflow.
This distinguishes it from quality estimation (QE), which is automated and predictive, generating scores before or during translation without human input. Quality evaluation is slower and more resource-intensive, but it captures what automated tools cannot: nuance, cultural appropriateness, brand voice, and contextual accuracy.
Most structured quality evaluation follows an established error framework. The most widely adopted in the localization industry is MQM (Multidimensional Quality Metrics), which categorizes errors by type accuracy, fluency, terminology, style, locale conventions, and assigns severity levels: neutral, minor, major, and critical. Each error type and severity carries a numerical weight, and the resulting score indicates overall translation quality against a defined threshold.
A common workflow: a sample of translated segments is selected (typically around 10% of the total project) and reviewed by a qualified linguist. Errors are logged, categorized, and scored. The overall quality metric score is compared against a threshold, such as 85 out of 100, to determine whether the translation passes or requires rework. Results are documented in a quality report that can be referenced for future projects, translator feedback, and workflow improvements.
These two terms share an abbreviation (QE) and are closely related but serve different purposes in the workflow:
| Quality evaluation | Quality estimation | |
|---|---|---|
| When | After translation | Before or during translation |
| How | Human review | Automated / ML-based |
| Requires reference | Yes | No |
| Speed | Slower, resource-intensive | Fast, scalable |
| Best for | Final quality assessment | Triage and routing decisions |
In practice, they are used together: quality estimation to route segments efficiently during production, and quality evaluation to validate the final output and continuously improve the translation platform.