Introduction: The aim of this study is to validate a Spanish version of the Impact of Event Scale on People with ID (IES-ID). Methods: IES-ID was administered to adults with ID (n = 120), analyzing internal consistency, inter-rater and test-retest reliability, criterion validity, construct validity and feasibility. Results: Good internal…

A measurement model describes both the numerical and theoretical relationship between observed scores and the corresponding latent variables or constructs. Testing a measurement model across groups is required to determine if the tests scores are tapping the same constructs so that the same meaning can be ascribed to the scores. Contemporary tests…

Examination of measurement invariance provides a powerful method to evaluate the hypothesis that the same set of psychological constructs underlies a set of test scores in different populations. If measurement invariance is observed, then the same psychological meaning can be ascribed to scores in both populations. In this study, the measurement…