Since the spring of 2004, 4^th, 8^th, and 10^th grade students in Montana have participated in the state assessment known as the Montana Comprehensive Assessment System (MontCas). The assessment is a Criterion Referenced Test (CRT) required by federal legislation under the Elementary and Secondary Education Act “No Child Left Behind”. A Criterion Referenced Test measures students’ academic proficiency according to the Montana state standards in reading and mathematics.  Student performance on the assessment is rated as novice, nearing proficient, proficient, or advanced.  Starting in the spring of 2006 all students in grades 3, 5, 6, and 7 also began participating in the Criterion Referenced Test. This spring, students in grades 4, 8, and 10 only will be assessed in Science as well as Reading and Math.