Cross-cultural measurement invariance of a developmental assessment tool in a small-scale intervention study

Development tests are widely used in the scope of cross-cultural and comparative research to support intervention studies and health care projects concerning early childhood development. Therefore, it is crucial to use culturally sensitive assessment tools. A culturally adapted version of the German development test FREDI 0-3 (Maehler, Cartschau, & Rohleder, 2016) was used to assess a German (n = 405) and an Indian (n = 2075) sample of children between ten and thirty-two months. Measurement invariance indicates psychometric equivalence of a construct across groups and is a prerequisite for test applications in a cross-cultural setting. Confirmatory factor analyses for single cohorts per age group and multi-group measurement invariance analyses were used to examine the data equivalence of the test across groups. Weak measurement invariance could be established across both groups in all four age groups (10-14; 15-21; 22-26; 27-32 months) suggesting that the development factor was measured in the same way in both groups and accounted similarly for performance differences in the developmental subdomains for the German and the Indian sample. However, scalar and strict measurement invariance were violated in almost all group comparisons suggesting differences in scale difficulty and reliability across the German and the Indian sample. This suggests that a culture-sensitive adaptation process like it was carried out within this project is necessary but not sufficient in order to create a culturally comparable development test. It is essential to always carry out measurement invariance testing to determine the psychometric equivalence of the test and additionally reduce linguistic and cultural bias through an adaption process based on empirical proven methodological principles.