In practice, vertical scales have been continually used to measure students' achievement progress across several grade levels and have been considered very challenging psychometric procedures. Recently, such practices have been drawing many criticisms. The major criticisms focus on dimensionality and construct equivalence of the latent trait or…

This document discusses in depth the theoretical background of the Lexile Framework, which is based on the assumption that reading comprehension is the best predictor of success in higher education and job performance, and that it is the most tested construct in education. The first section defines measurement and differentiates between specific…