The validation of ability scales describing multidimensional skills is always challenging, but not impossible. This study applies a multistage, criterion-referenced approach that uses a framework of aligned texts and reading tasks to explore the validity of the ACTFL and related reading proficiency guidelines. Rasch measurement and statistical analyses of data generated in three separate language studies confirm a significant difference in reading difficulty between the proficiency levels tested. (Contains 4 tables, 6 figures and 1 note.)