Findings from experimental studies have increasingly been used to inform policy in school settings. Thus far, the populations in many of these studies are typically defined in a cross-sectional context; namely, the populations are defined in the same academic year in which the study took place or the population is defined at a fixed time point.…

We expect that word knowledge accumulates gradually. This article draws on earlier approaches to assessing depth, but focuses on one dimension: richness of semantic knowledge. We present results from a study in which three distinct item types were developed at three levels of depth: knowledge of common usage patterns, knowledge of broad topical…

A vertical scale, in principle, provides a common metric across tests with differing difficulties (e.g., spanning multiple grades) so that statements of "absolute" growth can be made. This paper compares 16 states' 2007-2008 effect size growth trends on vertically scaled reading and math assessments across grades 3 to 8. Two patterns…