Rating scale development in the field of language assessment is often considered in dichotomous ways: It is assumed to be guided either by expert intuition or by drawing on performance data. Even though quite a few authors have argued that rating scale development is rarely so easily classifiable, this dyadic view has dominated language testing…

As a result of investigations showing that communication problems can be a significant contributing factor to major aviation accidents, the International Civil Aviation Organization (ICAO) has established a set of Language Proficiency Requirements. All pilots and air traffic controllers engaged in international aviation must be certified by their…