How is the ITBS Test Scored?
The ITBS® (Iowa Test of Basic Skills®) is scored based on your child’s age as well as the current month and grade level when the test is administered.
Here are all the steps used to calculate a child’s unique test score:
Standard Score (SS). The raw scores for each subtest are converted to Standard Scores that range from 80 to 400. A Standard Score indicates each student’s placement along an achievement continuum.
Grade Equivalent (GE). Grade Equivalent scores represent what the average student in the indicated level might score on the ITBS. Scores range from K.0 to 13+, with the first letter or number indicating current grade (K = Kindergarten, 1 = 1st grade, etc.) and the following decimal indicating a particular month in that school year. Example: 1.7 means the seventh month of 1st grade. The Grade Equivalent scores help administrators compare each child’s learning progress over time.
National Stanine (NS). National Stanine scores range from 1 (lowest) to 9 (highest possible score) and are both simplified and normalized by age and grade level.
National Percentile Rank (NPR). Each student’s National Percentile Rank score is calculated by comparing test performance against others within the same age range and grade level. A score in the 90th percentile means your child scored better than 90% of students on the Iowa test. The average rank in the U.S. is 50th percentile.