Norm versus Criterion referenced tests

Norm-referenced tests v. Criterion-referenced tests

In most schools past and present, tests have always been an integral component to a student’s success and achievement tests have always been starred on the school’s spring calendar of events. In our schools, student tests either compare students test scores to a broad range of students nationwide by percentage (looking for high and low achievers) and other tests are only measuring specific content that was presented in class that week or over a particular period of time. The purpose of this article is to simply explain the difference between norm-referenced tests (NRT) and Criterion-referenced tests (CRT) and how these styles apply to the tests administered in education today.

A criterion-referenced test is a test that does not compare test scores to a broad range of other students nationwide. However it determines whether or not a student has met the proficient level for that particular test for that test on that test date. For example, a classroom teacher who has created their own history test for a chapter test is measuring whether or not the students have learned the material that was presented to them during a particular time period. The proficiency level for that test would be set by the curriculum the school has in place. A common goal for classroom assessments is 80%, however that may not be true in many school districts (see your school’s curriculum content standards).

A norm-referenced test is a test that does compare students’ test scores to other students’ test scores across a broad range. Norm-referenced tests are compared by using percentiles. For example, a student in grade four taking the California Achievement Test (CAT) may have scored in the 67% in Math. That percentile score reflects that student’s performance amongst all fourth graders who took that same CAT that year.

In J.W. Popham’s Educational evaluation, the chart below clearly separates the differences in the two styles of tests by Purpose, Content, Item characteristics, and Score interpretation.

Dimension
Criterion-Referenced Tests (CRT)
Norm-Referenced Tests (CRT)

Purpose
CRT - To determine whether each student has achieved specific skills or concepts.
To find out how much students know before instruction begins and after it has finished.

NRT - To rank each student with respect to the
achievement of others in broad areas of knowledge.
To discriminate between high and low achievers.

Content
CRT - Measures specific skills which make up a designated curriculum. These skills are identified by teachers and curriculum experts. Each skill is expressed as an instructional objective.

NRT - Measures broad skill areas sampled from a variety of textbooks, syllabi, and the judgments of curriculum experts.

Item Characteristics
CRT - Each skill is tested by at least four items in order to obtain an adequate sample of student performance and to minimize the effect of guessing. The items which test any given skill are parallel in difficulty.

NRT - Each skill is usually tested by less than four items.
Items vary in difficulty. Items are selected that discriminate between high
and low achievers.

Score Interpretation
CRT - Each individual is compared with a preset standard for acceptable achievement. The performance of other examinees is irrelevant. A student's score is usually expressed as a percentage. Student achievement is reported for individual skills.

NRT - Each individual is compared with other examinees and assigned a score--usually expressed as a percentile, a grade equivalent score, or a stanine. Student achievement is reported for broad skill areas, although some norm-referenced tests do report student achievement for individual skills.

Popham, J. W. (1975). Educational evaluation. Englewood Cliffs, New Jersey: Prentice-Hall, Inc.

In my table below, I have listed many tests that New Jersey educators are familiar with. Let’s decide if the following tests are CRT, NRT or in some cases it can be both.

Regular & Special Education Tests

Grade Level Test CRT NRT can be both
All Teacher tests
Grade 3 NJASK 3
Grade 4 NJASK 4
Grade 5 NJASK 5
Grade 6 NJASK 6
Grade 7 NJASK 7
Grade 8 NJASK 8
Grades 9-12 End of Course (EOC’s)
Grade 11 HSPA
Grades 3,4,8,11 APA
Grades 9-12 AP exams
Grades 9-11 PSAT
Grades 9-12 SAT’s
Grades 9-12 ACT
Grades 9-12 GRE



Other examples of Achievement tests

Grade Level Test CRT NRT can be both
Grade K-12 CAT
Grade K - 8 IOWA
Grade K-12 Terra Nova
Age 16+ Driver’s test (NJ)


I hope these simple definitions and tables have helped you better understand the difference between a norm-referenced test versus a criterion-referenced test. No matter the design, achievement and accountability can always be measured.