For large-scale assessments, usually booklet designs administering the same item at different positions within a booklet are used. Therefore, the occurrence of position effects influencing the difficulty of the item is a crucial issue. Not taking learning or fatigue effects into account would result in a bias of estimated item difficulty. The…

The challenge inherent in cross-national research of providing instruments in different languages measuring the same construct is well known. But even instruments in a single language may be biased towards certain countries or regions due to local linguistic specificities. Consequently, it may be appropriate to use different versions of an…