Applications of item response theory to analysis of attitude scale translations.

Abstract

University of Illinois at Urbana-Champa ign Methods of detecting item bias developed from item response theory (IRT) are generalized to analyze the fidelity of translations of psychological scales into foreign languages. These IRT methods are considered as alternatives to classical methods. Item characteristic curves obtained from responses to the original and target language versions of the instrument are examined for significance of dif- ferences. Data from a Spanish translation of the Job Descriptive Index admin- istered to 203 Spanish-speaking employees are used to illustrate the method. Significance tests indicate that three items on the 72-item instrument are biased. Subsequent inspection of these three items by a language consultant revealed inadequate translation of one item. Because the number of items determined to be biased by significance testing is quite close to the expected number of Type I errors, it is concluded that the overall quality of the translation is quite good. Finally, it is argued that equivalent item characteristic curves across the original and translated items of a scale produce equivalent measurements in both lan- guages, and nonequivalent item characteristic curves pinpoint differences between the two versions of the scale. Two increasingly important areas of ap- plied psychological research are cross-cul- tural social psychology and cross-national in- dustrial-organizational psychology. The need to assess and make statements about differ- ences between cultures as well as within cul- tures is an integral part of both areas. Herein lies the problem addressed in this article: Cross-cultural research depends on cross-cul- tural comparisons, which, in turn, usually depend upon the meaningfulness of measur-