Norm-Referenced Tests

Norm-referenced tests compare an individual's score to a representative sample of scores obtained from the same measure. The norm group is typically drawn from the general population. Tests are normed by selecting a group that is drawn from the general population and may be matched on variables such as gender, age, race/ethnicity, socioeconomic status, type of school, grade level, and others. An individual's score is then directly compared to the individual's norm group. The standardization of a norm-referenced test creates a scale in which an individual's score results in a ranking within the scores obtained from the norm group (Sattler, 2001). The score is determined to be high or low based on the scores obtained from the norm group.

In educational and school psychology, normreferenced tests are an important tool that serves many functions. Norm-referenced tests may provide information that may not be obtained from other sources. Norm-referenced tests have been used to obtain information on intelligence, achievement, and behavior (Sattler, 2001). They may also be used to gather information on students’ rankings on broad educational outcomes such as math calculation or reading comprehension. Additionally, information gathered from norm-referenced tests can be used to identify children with special needs. Thus, the scores derived from these tests may lead educators to place students with special services.

Witt and colleagues (1998) describe several advantages and disadvantages of using normreferenced tests in educational settings. One advantage of norm-referenced tests is to help determine whether students require special services. Students may receive special services based on how their scores fall within their normative group. Another advantage of norm-referenced tests is that they do not usually require an extensive amount of time to administer. A third advantage is that scores derived from norm-referenced tests are typically easy to explain to parents. For example, most parents understand what it means for their child to perform at the 99th percentile. Of all individuals taking the test, their child performed better than 99% of the test takers. Finally, another advantage of norm-referenced tests is that there is an abundance of technical data supporting the tests’ standardization, reliability, and validity.

There are some disadvantages of using normreferenced tests in educational settings. One disadvantage is that the information gathered from a norm-referenced test is often too broad in scope and does not inform educators of students’ specific weaknesses that may be in need of remediation. By the same token, information from norm-referenced tests does not inform students’ educators of academic strengths. Another disadvantage of using normreferenced tests is that the items on the tests are not typically derived from students’ current curriculum. Therefore, the norm-referenced test is assessing broad educational knowledge, but not classroom content.

There are many examples of norm-referenced tests in current use in educational settings. One is the California Achievement Test (CAT), which is a groupadministered achievement test frequently used by public school systems. The CAT's standardization sample consists of thousands of students drawn from across the nation. The CAT's standardization sample is stratified by grade level, type of school, geographic region, and community type.

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