Students participate in a number of standardized tests as part of their educational experience. Standardized tests are tests that are administered and scored the same way for all students. There are two kinds of standardized tests: norm-referenced and criterion-referenced.
Norm-Referenced Tests (NRTs) compare a student’s performance to that of other test-takers. Students take the test and are compared to a similar group of students who took the test nationally (the norm group).
Some examples of NRTs each student might take are:
District Common Assessments (DCAs) compare a student’s performance to clearly identified grade level criteria. The basis for comparison is a body of knowledge and skills.
National Percentile Ranks (or National Percentiles) tell you the percent of students a child outscored on the exam. They range from a low of 1 to a high of 99, with average performance at 50. For example, a student who performed as well as or better than 75% of the students in the national group would earn a percentile rank of 75.
National percentile ranks indicate the relative standing of a student or group of students in comparison with other students in the same grade level who took the test at a comparable time (for example, April). They can also be used to compare a student’s or group of students’ performance across tests in the battery. A student’s score report may include percentile rank scores and a graph with gray bands. If you want to compare a student’s performance across subject areas, you need to look at the gray bands. The bands account for error in the test scores. If the bands for two subject areas do not overlap on the graph, then your child is achieving higher in one of those subject areas. For example if your student received a percentile rank of 33 in reading and 56 in math, the gray bands might range from 26 to 40 in reading and from 48 to 64 in math. The bands for math and reading would not overlap on the graph, so you would know that a student’s performance was higher in math.
When making comparisons between subject areas or grade levels for whole groups of students, a difference of at least 5 percentile ranks is meaningful (one not caused by error in the scores). For example, if second-grade students received a national percentile rank of 65 in total reading and a national percentile rank of 73 in math, we could conclude that these second graders performed better in math than in reading.
Stanines are scores that range from a low of 1 to a high of 9, with an average of 5. Stanines, like percentile ranks show a student’s or group of students’ performance compared to a group of students who took the test nationally. Stanines make it easy to identify broad performance categories. Stanines of 1, 2, or 3 are usually considered to reflect below-average performance; stanines of 4, 5, or 6 are generally thought of as average; and stanines of 7, 8, or 9 are above average. Differences of at least 2 stanines are considered to be meaningful differences for both individual students and for groups of students.