APA Dictionary of Psychology

an achievement battery providing tests for reading, language, mathematics, social studies, science, and sources of information for students in kindergarten through Grade 8. It is divided into 10 skill levels (numbered 5 through 14) according to grade, with norms for the beginning, middle, and end of each academic year. The numerical label of each level reflects the approximate age of the children for which it is intended (e.g., Level 9 is administered to students in Grade 3, who are typically 9 years old). The various subtests of the ITBS are designed to measure the higher level cognitive functions considered basic to succeeding in school, such as interpretation, classification, comparison, and analysis. The ITBS, originally developed at the University of Iowa in 1935 as the Iowa Every Pupil Test of Basic Skills, was revised most recently in 2001, 2003, and 2007.