The Iowa Test of Basic Skills (ITBS) is a standardized test given to students in grades 2-8. The ITBS measures achievement and critical thinking skills in Reading, Language, Mathematics, Social Studies, Science and Sources of Information. The test is norm referenced, which means 50% is the average number of students who get an item correct nationally. The primary purpose is to measure individual student growth and to guide teacher instruction in all subject areas. In addition to the ITBS the 3rd, 5th and 7th grade students take the CogAT which is a Cognitive Abilities Test.