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What is LQA? Complete Guide to Linguistic Quality Assurance

KTTC Team1/4/20259 min read
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Linguistic Quality Assurance (LQA) is a systematic process for evaluating the quality of translated content. It goes beyond simple proofreading to provide objective, measurable assessments of translation accuracy, fluency, and overall fitness for purpose.

In this comprehensive guide, you'll learn everything about LQA: what it is, how it works, and how to implement it effectively in your translation workflow.

What is LQA?

LQA (Linguistic Quality Assurance) is the process of evaluating translated content against defined quality standards. Unlike general proofreading, LQA uses structured methodologies—typically based on error typologies like MQM—to identify, categorize, and score translation errors.

LQA vs. Proofreading vs. Editing

ActivityFocusOutput
ProofreadingFixing surface errorsCorrected text
EditingImproving style and clarityEnhanced text
LQAEvaluating quality objectivelyQuality score + error report

The key difference: LQA measures quality rather than just fixes problems. This measurement enables:

  • Vendor performance comparison
  • Quality trend tracking
  • Objective feedback for translators
  • SLA compliance verification

Why LQA Matters

1. Quality Consistency

Without LQA, quality varies unpredictably between translators, projects, and languages. LQA establishes consistent standards across all translations.

2. Cost Control

Poor translations are expensive. Rework, customer complaints, and brand damage cost far more than proper quality assurance. LQA catches issues early.

3. Vendor Management

When working with multiple translators or agencies, LQA provides objective data for performance evaluation and improvement.

4. Compliance

Industries like healthcare, legal, and finance require documented quality processes. LQA provides the audit trail.

5. Continuous Improvement

By tracking error patterns, LQA identifies systemic issues that can be addressed through training or process changes.

The LQA Process

A typical LQA workflow includes these steps:

Step 1: Define Quality Criteria

Before evaluation, establish:

  • Error categories to track (accuracy, fluency, terminology, etc.)
  • Severity levels (critical, major, minor)
  • Passing threshold (e.g., MQM score ≥95)
  • Sample size (100% or representative sample)

Step 2: Select Evaluators

LQA evaluators should be:

  • Native speakers of the target language
  • Subject matter experts (for specialized content)
  • Trained in the LQA methodology
  • Independent from the original translators

Step 3: Perform Evaluation

Evaluators review translations segment by segment, identifying errors and categorizing them by:

  • Error type (mistranslation, omission, grammar, etc.)
  • Severity (how much impact does this error have?)
  • Location (which segment contains the error?)

Step 4: Calculate Quality Score

Using a scoring model like MQM:

Quality Score = 100 - (Penalty Points / Word Count × 100) 

Where penalty points depend on error severity:

  • Critical: 25 points
  • Major: 5 points
  • Minor: 1 point

Step 5: Generate Reports

LQA reports typically include:

  • Overall quality score
  • Error breakdown by category
  • Error breakdown by severity
  • Specific error annotations with examples
  • Comparison with historical performance

Step 6: Feedback Loop

Share LQA findings with translators for continuous improvement. Focus on:

  • Patterns in error types
  • Specific examples with correct alternatives
  • Recognition for high-quality work

LQA Error Categories

Based on the MQM framework, common LQA error categories include:

Accuracy Errors

Error TypeDescriptionExample
MistranslationMeaning incorrectly conveyed"annual" → "monthly"
OmissionContent missing from translationSkipped sentence
AdditionExtra content not in sourceUnexplained additions
UntranslatedSource text left as-isEnglish term in Spanish text

Fluency Errors

Error TypeDescriptionExample
GrammarGrammatical mistakes"The datas is..."
SpellingMisspelled words"recieve"
PunctuationIncorrect punctuationMissing comma
TypographyFont, spacing issuesDouble spaces

Terminology Errors

Error TypeDescriptionExample
Wrong termIncorrect terminology"mouse" as animal vs. device
InconsistencySame term translated differentlyVarying product names
Unapproved termTerm not in client glossaryUsing alternative without approval

Style Errors

Error TypeDescriptionExample
RegisterWrong formality level"you" vs. formal equivalent
UnidiomaticAwkward phrasingLiteral translation that sounds wrong
Inconsistent styleVarying tone within documentMixing formal and casual

Locale Errors

Error TypeDescriptionExample
Date formatWrong date convention12/31/2025 vs. 31/12/2025
Number formatWrong decimal/thousand separator1.000 vs. 1,000
CurrencyIncorrect currency handlingWrong symbol or format

LQA Severity Levels

Critical Errors

Errors that could cause:

  • Legal liability
  • Safety risks
  • Financial loss
  • Severe misunderstanding

Examples: Medical dosage errors, legal term mistakes, safety instruction omissions

Typical Penalty: 25 points

Major Errors

Errors that significantly impact:

  • Comprehension
  • User experience
  • Professional appearance

Examples: Wrong meaning, confusing sentence structure, inappropriate tone

Typical Penalty: 5 points

Minor Errors

Errors with minimal impact:

  • Noticed but don't affect understanding
  • Minor stylistic issues
  • Small typos

Examples: Minor punctuation, slight awkwardness, capitalization

Typical Penalty: 1 point

LQA Metrics and KPIs

Quality Score (MQM-based)

The primary metric. Calculated as:

Score = 100 - (Total Penalty / Word Count × 100) 

Error Rate

Errors per 1000 words:

Error Rate = (Total Errors / Word Count) × 1000 

Pass Rate

Percentage of translations meeting quality threshold:

Pass Rate = (Passing Translations / Total Translations) × 100 

Error Distribution

Breakdown of errors by:

  • Category (accuracy, fluency, etc.)
  • Severity (critical, major, minor)
  • Translator or vendor

AI-Powered LQA

In 2025, AI is transforming LQA:

Traditional LQA vs. AI LQA

AspectTraditional LQAAI LQA
SpeedHours per documentMinutes per document
CostHigh (human evaluator time)Lower per evaluation
ConsistencyVaries by evaluatorHighly consistent
ScalabilityLimitedVirtually unlimited
NuanceExcellentGood and improving

How AI LQA Works

Modern AI LQA tools use large language models to:

  1. Compare source and target texts
  2. Identify potential errors
  3. Classify errors by type and severity
  4. Calculate quality scores
  5. Generate detailed reports

AI LQA Limitations

While powerful, AI LQA has limitations:

  • May miss subtle cultural nuances
  • Can struggle with highly creative content
  • Requires human validation for critical content
  • Not yet suitable for final quality decisions in regulated industries

Best Practice: Hybrid Approach

Combine AI and human LQA:

  1. AI first - Quick initial assessment at scale
  2. Human review - Verify AI findings, especially critical errors
  3. Random sampling - Human spot-checks on AI-passed content
  4. Continuous calibration - Use human feedback to improve AI accuracy

Implementing LQA in Your Organization

Step 1: Choose Your Framework

Select an error typology:

  • MQM - Industry standard, highly customizable
  • LISA QA - Legacy but still used
  • Custom - Based on specific needs

Step 2: Define Quality Tiers

Not all content needs the same quality level:

TierContent TypeLQA IntensityPass Threshold
PremiumLegal, medical, marketing100% review98+
StandardBusiness, documentation20% sample95+
BasicInternal, user-generatedAI-only90+

Step 3: Select Tools

LQA tools range from:

  • Spreadsheets - Simple but manual
  • Dedicated LQA tools - Purpose-built for translation QA
  • TMS-integrated - Built into your translation management system
  • AI-powered platforms - Like KTTC with automated LQA

Step 4: Train Your Team

Ensure evaluators understand:

  • Error category definitions
  • Severity criteria
  • Tool usage
  • Calibration processes

Step 5: Establish Calibration

Regular calibration ensures consistency:

  • Evaluate same content independently
  • Compare results and discuss discrepancies
  • Update guidelines based on learnings

FAQ

What does LQA mean in translation?

LQA stands for Linguistic Quality Assurance. It's the process of systematically evaluating translation quality using standardized error categories, severity levels, and scoring systems. LQA provides objective, measurable quality assessments rather than subjective opinions.

What is the difference between LQA and QA?

QA (Quality Assurance) is a broad term covering all quality-related activities. LQA specifically focuses on linguistic aspects of translation quality—accuracy, fluency, terminology, style, and locale conventions. Technical QA might cover formatting, functionality, or user experience issues that aren't linguistic.

How is LQA score calculated?

LQA scores are typically calculated using the MQM (Multidimensional Quality Metrics) model. Errors are identified, categorized by type and severity, and assigned penalty points. The score equals 100 minus the total penalty divided by word count times 100. For example: 100 - (15 penalty points / 1000 words × 100) = 98.5.

What is a good LQA score?

A good LQA score depends on content type and use case. Generally: 99-100 is excellent (publishable as-is), 95-98 is good (minor review needed), 90-94 is acceptable (corrections required), and below 90 typically requires significant revision. Critical content like legal or medical documents often requires 98+.

Can AI replace human LQA evaluators?

Not entirely. AI LQA is excellent for initial screening, consistency, and scale, but human evaluators remain essential for nuanced judgment, cultural adaptation assessment, and validation of critical content. The 2025 best practice is a hybrid approach combining AI efficiency with human expertise.

Conclusion

Linguistic Quality Assurance is essential for professional translation. By implementing structured LQA processes, organizations can ensure consistent quality, manage vendors effectively, and continuously improve their translation operations.

Whether you're using traditional human LQA, AI-powered tools, or a hybrid approach, the key is having a systematic, measurable process that provides actionable insights.

Ready to implement LQA in your translation workflow? Try KTTC for AI-powered linguistic quality assurance with MQM-based evaluation and comprehensive error reporting.

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