Translation and Adaptation of Psychological Tests

The translation and adaptation of psychological tests used for practice and research requires careful attention to issues of bias and equivalence. Thorough translation methods help reduce bias and enhance [Page 419]equivalence of multilingual versions of a test. Of equal importance is statistical verification of equivalence.

Equivalence addresses the question of comparability of observations and test scores across cultures. Lonner described four types: functional, conceptual, metric, and linguistic equivalence. These refer to issues of comparability of behavior and concepts across cultures to issues of test item characteristics (form, meaning structure). Van de Vijver also discussed four types of equivalence. Construct noneqaiw-alence refers to constructs being so dissimilar across cultures they cannot be compared. Construct equivalence occurs when a scale measures the same underlying construct and nomological network across cultural groups, but may not be defined the same way. With measurement unit equivalence, the measurement scales for the instruments are equivalent (e.g., interval level), but their origins are different across groups. Equivalence at this level may limit comparability of two language versions of an instrument. The origins of the two versions may appear the same (both include interval scales), but because of differential familiarity with the response format used (e.g., Likert scale), the two versions are not identical. The same holds if the two cultural groups vary in response style (e.g., acquiescence). At the highest level of equivalence is scalar equivalence or full score comparability. Equivalent instruments at this level measure a concept with the same interval/ratio scale across cultures and the origins of the scales are similar. At this level, bias has been ruled out and direct cross-cultural comparisons of scores on an instrument can be made.

Bias negatively influences equivalence and refers to factors limiting comparability of test scores across cultural groups. Construct bias occurs when a construct is not identical across cultural groups (e.g., incomplete construct coverage). Method bias may limit scalar equivalence and can stem from specific characteristics of the instrument (e.g., differential response styles) or from its administration. Item bias can result from poor translation and item formulation and because item content may not be equally relevant across cultural groups.

Use of proper translation procedures can minimize bias and help establish equivalence. The International Test Commission (ITC) published translation guidelines to encourage attention to the cross-cultural validity of translated or adapted instruments. The context guidelines emphasize minimizing construct, method, and item bias, and assessing construct similarity or equivalence across cultural groups before embarking on instrument translation. The development guidelines refer to the translation process itself, while the administration guidelines suggest ways to minimize method bias. The interpretation guidelines recommend verification of equivalence between language versions of an instrument.

Two general approaches have been identified when translating or adapting tests. In the applied approach, items are literally translated. Item content is not changed to a new cultural context, and the linguistic and psychological appropriateness of the items are assumed. With the adaptation approach, some items may be literally translated while others require modification of wording and content to enhance their appropriateness to a new culture. This approach is chosen if there is concern with construct bias. For both approaches, attention to equivalence and absence of bias is important. Building on the ITC guidelines and the work of others, the following should be considered when translating or adapting tests.

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