The bilingual study methodology in translating and adapting personality tests: Equivalence issues in the development of the MMPI-2-RF Portuguese version

Abstract

The bilingual samples’ studies are listed as a useful tool to confirm the equivalence between linguistically different versions of a test. Yet, such studies are rare in the literature, as they require technical issues to be considered before any conclusion about equivalence can be reached. This paper discusses some of these issues, taking the example of the recent MMPI-2-RF Portuguese adaptation and standardization study. The results of a bilingual study (N = 53) using a single-sample design are analyzed, at item, scale, profile, and structural levels, allowing an encouraging general conclusion about the equivalence of the Portuguese MMPI-2-RF to the North American original version, but also pointing out some directions for improvement. The shortcomings of the classical bilingual studies, and the specific limitations due to the obstacles to bilingual samples’ recruitment in Portugal, are considered. The limited sample size and some other methodological shortcomings are discussed, considering their implications for future Portuguese MMPI equivalence studies.