This study reanalyzes data presented by Ritchie, Bates, and Plomin (2015) who used a cross-lagged monozygotic twin differences design to test whether reading ability caused changes in intelligence. The authors used data from a sample of 1,890 monozygotic twin pairs tested on reading ability and intelligence at five occasions between the ages of 7…

The popularity of growth modeling has increased in psychological and cognitive development research as a means to investigate patterns of changes and differences between observation units over time. Random coefficient modeling, such as multilevel modeling and latent growth curve modeling as a special application of structural equation modeling are…

Items from a widely used standardized reading achievement test were rated by trained judges according to the degree to which they required an understanding of hierarchical classification. Two subtests were constructed from subsets of items that were identified by their extreme ratings. Subtest A was judged to require classification operations from…

Reviews the 3-R's Test that measures achievement in three academic content areas: reading, language, and mathematics. Cautions that it lacks data supporting its validity and scaling. (HOD)