Measurement invariance (MI) is a property of measurement that is often implicitly assumed, but in many cases, not tested. When the assumption of MI is tested, it generally involves determining if the measurement holds longitudinally or cross-culturally. A growing literature shows that other groupings can, and should, be considered as well.…

The research from a four-year project of implied orders tailored testing is summarized. The method of implied orders testing combines the principles of ordinal measurement with the concept of the Guttman scale as an ideal. The basic principle for dichotomous items is that either an item is missed and "dominates" a person or it is answered…