Adapting a psychological test to another language and culture
Adapting a psychological test aims to preserve what it measures when its language and cultural setting change. The work extends beyond readable translation to decisions about suitability, content, administration, psychometric evidence and fairness, with consequences for the people whose scores guide decisions.
Meaning and aims of adaptation
Tests measure behaviour and mental attributes through items, standardised procedures and established evidence of reliability or precision, validity and fairness; knowledge tests, questionnaires, scales and inventories are examples. Mental-health testing extends beyond clinical trials to behavioural and social research, education, clinical practice, forensics and organisational psychology. Outside clinical research, “tests” and “test adaptation” replace the terms “clinical outcome assessments” and “linguistic validation”.
Test adaptation moves a test between languages and cultures, prioritising intent rather than translated content alone. It evaluates psychometric appropriateness as well as readability and presentation, aiming to measure the same construct, maximise fairness, minimise bias, achieve sufficient reliability or precision and maintain validity for the intended uses. The process is multistep and iterative, from deciding whether adaptation is needed or possible to selecting translators and conducting validation studies.
Consequences of an unsuitable test
In a Colombian neuropsychological-assessment practice, patients were given an unadapted US English naming test requiring them to identify pictures. Many mistook a beaver for a rat or a pretzel for a snake, while affluent patients with previous exposure to US culture could identify them. The items reflected factors such as socioeconomic status rather than naming ability, so scores could not support diagnoses or recommendations; interpreting them otherwise could have suggested widespread aphasia among lower-income patients.
Poor questionnaire translation in a clinical trial can impair assessment of efficacy or group differences, but results are typically analysed in aggregate. In applied mental health, poor adaptation can instead directly affect individuals, often in vulnerable circumstances. Tests that are not equivalent can produce incorrect conclusions affecting accommodations, benefits, diagnoses, treatment, financial aid, employment, scholarships and adoption.
Planning the adaptation
A recommended planning process has four steps:
- Identify and define the need. Establish the applied use, such as clinical assessment of a condition in another country, or the small- or large-scale research use, such as international social or educational research.
- Decide whether to adapt. A test validated in English, in one culture, with English instructions and English-speaking participants and administrators supports valid interpretation only in that context. Developing a new test is an alternative. Adaptation can make comparisons between cultural and language groups easier, save time and money, provide an option where local subject-specific psychometric expertise is unavailable, and extend an established instrument's reputation.
- Determine the approach. Simply replacing unfamiliar pictures and beginning to administer a test is insufficient. Research allows more flexibility in reliability or precision and validity criteria than applied use; comparability after translation must be proved. Consider the test's characteristics, target population, construct, geography and administration mode, such as computer versus paper.
- Use established standards. The Standards for Educational and Psychological Testing address validity, fairness, reliability or precision and ethics and are considered the gold standard; FDA draft clinical-outcome-assessment guidance described in 2024 also used them as a foundation. The International Test Commission provides adaptation guidelines and checklists and, with the Association of Test Publishers, guidance for technology-based assessment. Guidelines for Best Practice in Cross-Cultural Surveys cover questionnaire design and translation for multinational, multicultural and multiregional surveys; methods for large-scale assessments such as PISA surveys provide further approaches.
Test characteristics differ substantially: the Beck Depression Inventory-II is a short, straightforward self-report inventory of depressive attitudes and symptoms, while NEPSY-II is a lengthy six-domain assessment of children's neuropsychological status through tasks such as hand-position imitation, block construction and looking at faces in photographs. KIDSCREEN assesses children's health-related quality of life, including psychological wellbeing, moods, emotions and bullying, within a large European research project. A brief clinical screen, a diagnostic test and an international public-health research instrument therefore need different approaches, as do populations such as children, young adults with intellectual disability and adults seeking work.
Content affected by language and culture
Test content includes the themes, wording and format of items, tasks and questions, together with administration and scoring. Linguistic and cultural components that may need adaptation include:
| Component | Possible changes and examples |
|---|---|
| Currencies | Change currency, amounts or denominations; knowledge of dimes, cents or pennies is culturally influenced, so direct conversion may not work. |
| Measures | Change between imperial, metric or US customary systems, convert or round amounts; teaspoons in a recipe item may become millilitres or grams. |
| Sport | Use familiar sports; sumo-rule questions may be unsuitable for European test takers. |
| Geography | Use culturally relevant references; the number of continents recognised can range from four to seven. |
| Numbers | Consider written and spoken forms and complexity; 20.000 can mean twenty with three decimal zeros or twenty thousand. |
| Art | Use locally relevant references; Colombian painter Fernando Botero may be less familiar elsewhere. |
| History | Adapt references; the Mexican Revolution is a more accessible question for students in Mexico than Nigeria. |
| Daily life | Significantly adapt or replace references to education, food, animals or activities; typical shop opening times differ, for example 7 am in Colombia and 9 am in Spain. |
Translator expertise and error control
Adaptation faces three sources of error or invalidity: cultural and language differences; technical issues, designs and methods; and interpretation of results. Translators help mitigate these, particularly technical and methodological errors involving test content, the translators and the translation process. They must have expert source- and target-language and cultural knowledge, deeply understand the test's content and testing principles.
Even translating “tree” changes a one-syllable English word to a two-syllable Spanish word, and using the same word does not guarantee equivalent familiarity, frequency, difficulty or item location. The relevance of such details depends on the item's intent, construct and translator instructions. Translators should identify, address, document and communicate them, consulting the team rather than dismissing them or making unilateral changes.
Quality-control procedures check the translation against adaptation objectives. Outside clinical trials, approaches go beyond back-translation to hybrid designs with multiple iterations, steps and checks. Translation is followed by statistical analysis, norming and publication, which fall outside the translator's scope.
A robust procedure and compliance with established guidance are essential, yet equivalence is not guaranteed even after linguistic quality control. Validity, reliability or precision and fairness require continuing work; translators contribute by minimising errors, documenting decisions and reporting potential problems to subject-matter experts and psychometricians to support their decisions.