MQM Framework: Complete Guide to Translation Quality Metrics 2025
Multidimensional Quality Metrics (MQM) is the industry-standard framework for evaluating translation quality. Developed as part of the EU-funded QTLaunchPad project and now backed by ISO standards, MQM provides a systematic, objective approach to translation quality assessment.
In this comprehensive guide, you'll learn what MQM is, how it works, and how to implement it in your translation workflow.
What is MQM?
MQM (Multidimensional Quality Metrics) is a framework for analytic Translation Quality Evaluation (TQE). Unlike subjective quality reviews, MQM provides a standardized error typology and scoring system that can be applied consistently across projects, languages, and evaluators.
Key Features of MQM
- Standardized error typology with clearly defined categories
- Severity levels (Critical, Major, Minor) for each error type
- Flexible configuration to match project requirements
- ISO alignment through ISO 5060:2024 and ISO 11669:2024
- Applicable to both human and machine translation
Why MQM Matters in 2025
The translation industry has evolved significantly with the rise of AI and machine translation. In 2025, MQM is more relevant than ever because:
AI Translation Needs Objective Measurement - With LLMs like GPT-4 and Claude producing increasingly fluent translations, we need rigorous metrics to evaluate actual quality, not just fluency.
Client Expectations Are Higher - Enterprise clients demand measurable quality standards and consistent deliverables.
ISO Standards Require It - The new ISO 5060:2024 standard for translation quality evaluation is based on MQM principles.
Vendor Performance Tracking - Agencies use MQM to objectively compare translator and MT engine performance.
MQM Error Categories Explained
MQM organizes translation errors into a hierarchical typology. Here are the main categories:
1. Accuracy Errors
Errors related to the faithfulness of the translation to the source text.
| Error Type | Description | Example |
|---|---|---|
| Mistranslation | Incorrect meaning transfer | "annual report" translated as "monthly report" |
| Omission | Source content missing in target | A sentence from the source not translated |
| Addition | Extra content not in source | Translator added explanation not in original |
| Untranslated | Source text left in target | Technical term left in English in German text |
2. Fluency Errors
Errors affecting the natural flow of the target text.
| Error Type | Description | Example |
|---|---|---|
| Grammar | Grammatical mistakes | Subject-verb disagreement |
| Spelling | Orthographic errors | "recieve" instead of "receive" |
| Punctuation | Incorrect punctuation | Missing comma in a compound sentence |
| Inconsistency | Inconsistent usage | Same term translated differently |
3. Terminology Errors
Errors related to specialized vocabulary.
| Error Type | Description | Example |
|---|---|---|
| Wrong term | Incorrect terminology used | "computer mouse" translated as "animal mouse" |
| Inconsistent terminology | Same term translated differently | "user interface" and "UI" used interchangeably when client requires one |
4. Style Errors
Errors related to style guide compliance.
| Error Type | Description | Example |
|---|---|---|
| Register | Wrong formality level | Using informal "you" when formal is required |
| Unidiomatic | Awkward but not incorrect | Literal translation that sounds unnatural |
5. Locale Errors
Errors in locale-specific conventions.
| Error Type | Description | Example |
|---|---|---|
| Date format | Wrong date convention | MM/DD/YYYY in European locale |
| Currency | Incorrect currency handling | $ symbol for EUR amounts |
| Measurement | Wrong unit system | Miles instead of kilometers |
MQM Severity Levels
Each error is assigned a severity level that affects the quality score:
| Severity | Description | Typical Penalty |
|---|---|---|
| Critical | Errors causing serious harm (legal, safety, financial) | 25 points |
| Major | Errors significantly impacting understanding or usability | 5 points |
| Minor | Errors with minimal impact on understanding | 1 point |
How to Determine Severity
- Critical: Would this error cause legal liability, safety risks, or significant financial loss?
- Major: Does this error prevent understanding or create significant confusion?
- Minor: Is this a noticeable error that doesn't significantly impact comprehension?
MQM Scoring Model
The MQM score is calculated based on errors found during evaluation:
MQM Score = 100 - (Total Penalty Points / Word Count × 100) Example Calculation
For a 1000-word document with:
- 2 Major errors (5 × 2 = 10 points)
- 5 Minor errors (1 × 5 = 5 points)
- Total penalty: 15 points
MQM Score = 100 - (15 / 1000 × 100) = 98.5
Quality Thresholds
Typical industry thresholds:
| Score Range | Quality Level | Action Required |
|---|---|---|
| 99-100 | Excellent | Ready for delivery |
| 95-98 | Good | Minor review recommended |
| 90-94 | Acceptable | Review and corrections needed |
| Below 90 | Poor | Significant rework required |
How to Implement MQM in Your Workflow
Step 1: Define Your MQM Profile
Not every project needs all error categories. Create a custom MQM profile based on:
- Content type (marketing, legal, technical)
- Target audience (consumers, professionals)
- Quality requirements (publishable, informational)
Step 2: Train Your Evaluators
Consistent application requires trained evaluators who understand:
- Error category definitions
- Severity level criteria
- Project-specific requirements
Step 3: Select Sample Size
For statistical validity, evaluate a representative sample:
- Minimum: 250-500 words per document
- Recommended: 10-15% of total word count
- High-stakes: 100% evaluation for critical content
Step 4: Document and Analyze Results
Track MQM scores over time to:
- Identify patterns in error types
- Measure translator or MT engine improvement
- Provide actionable feedback
MQM vs Other Quality Frameworks
MQM vs LISA QA Model
| Aspect | MQM | LISA QA |
|---|---|---|
| Error categories | Comprehensive, hierarchical | Fixed categories |
| Customization | Highly flexible | Limited |
| ISO backing | Yes (ISO 5060) | No |
| Industry adoption | Growing standard | Legacy |
MQM vs DQF (TAUS)
MQM and DQF (Dynamic Quality Framework) have merged efforts. DQF now uses MQM error typology, making them complementary rather than competing frameworks.
Tools Supporting MQM
Several translation quality tools support MQM-based evaluation:
- KTTC - Full MQM support with automated error detection
- Phrase Quality Assessment - Enterprise MQM implementation
- TAUS DQF - Industry benchmarking with MQM
- memoQ - Built-in QA with MQM categories
FAQ
What does MQM stand for?
MQM stands for Multidimensional Quality Metrics. It's a framework for systematically evaluating and measuring translation quality using standardized error categories and severity levels.
Is MQM an ISO standard?
MQM principles are incorporated into ISO 5060:2024 (Translation quality evaluation) and align with ISO 11669:2024 (Translation projects). While MQM itself is a framework, it provides the error typology foundation for these international standards.
How many error categories does MQM have?
The full MQM framework contains over 100 error types organized hierarchically. However, most implementations use a subset of 20-40 categories relevant to their specific use case. The main top-level categories are Accuracy, Fluency, Terminology, Style, and Locale conventions.
Can MQM be used for machine translation evaluation?
Yes, MQM is widely used for MT evaluation. The WMT (Workshop on Machine Translation) shared tasks use MQM-based annotations for human evaluation of machine translation systems. MQM helps objectively compare MT outputs from different engines.
What is a good MQM score?
A good MQM score depends on the content type and use case. Generally, scores above 95 are considered publishable quality, 90-95 is acceptable for most purposes, and scores below 90 typically require revision. Critical content like legal or medical documents often requires 99+.
Conclusion
MQM provides the translation industry with a rigorous, standardized approach to quality measurement. As AI translation becomes more prevalent and quality expectations rise, frameworks like MQM are essential for objective evaluation.
Whether you're a translation agency evaluating vendor performance, a client specifying quality requirements, or a linguist improving your craft, understanding MQM is a valuable investment in translation excellence.
Ready to implement MQM in your workflow? Try KTTC's MQM-based quality assessment and see the difference objective quality metrics can make.