Testing psychometric properties of the CFT 1-R for students with special educational needs

The Culture Fair Intelligence Test CFT 1-R [...] is one of the most used tests in Germany when diagnosing learning disabilities (LD). The test is constructed according to the classical test theory and provides age specific norms for students with LD in special schools. In [this] study, [the authors] analyzed the test results of 138 students in special schools and 166 students with LD in inclusive settings in order to test the measurement invariance between students with LD, who are educated in these two different educational settings. Data were analyzed within an IRT framework using a non-iterative approach for (item) parameter recovery. This approach parallels with the principle of limited information estimation, which allows for IRT analyses based on small datasets. Analyses for Differential Item Functioning (DIF) as well as a test for global and local model violations with regard to both subgroups were conducted. The results confirmed the assumption of measurement invariance across inclusive and exclusive educational settings for students with LD. (Orig.).