Gender differential item functioning in Slovak version of neo five factor inventory

Objectives. Presence of differential item functioning (DIF) in psychological measurement tools can indicate the presence of bias between groups. The present study is focused on analysing DIF between males and females in the Slovak version of NEO Five Factor Inventory (NEO-FFI). Sample and settings. The sample consists of 1016 respondents (40,6% males) from Slovakia, with mean age of 25.97 years (SD=13.42). Statistical analysis. For DIF analysis Mantel’s test in DIFAS 5.0 software, ordinal logistic regression and Poly-SIBTEST were used. Results. The final results show 18 items with medium and large uniform DIF, 6 of them identified by all the methods used. One item showing purely non-uniform DIF was identified. Deletion of identified DIF items caused notable change in scale score differences between males and females in Openness to experience scale. Possible factors causing DIF are discussed. Presence of the identified DIF items does not suggest that NEO-FFI is severely biased against males or females. Limitation. Limitation of the present study lies mainly in the general sample. Future studies should verify these findings on age specific samples.