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California Achievement Tests


The California Achievement Tests (CAT) are among the most widely used tests of basic academic skills for children from kindergarten through grade 12. The most recent edition of the CAT (the sixth) is also called TerraNova, Second Edition (or alternately, Terra-Nova CAT ).


The CAT is often administered to determine a child's readiness for promotion to a more advanced grade level and may also be used by schools to satisfy state or local testing requirements.


First introduced in 1950, the CAT is a paper-and-pencil test for children from kindergarten through grade 12 that is designed to measure academic competency in a variety of areas. The test is available in six different forms: CAT Complete Battery, CAT Basic Battery, CAT Survey (grades two through 12 only), and CAT Plus.

The CAT is a standardized test, meaning that norms were established during the design phase of the test by administering the test to a large, representative sample of the test population (in the case of the CAT, over 300,000 students). The test is given in a group, classroom setting, and can take anywhere from one-and-a-half to over five hours to complete depending on the test form and grade level. A teacher typically administers the CAT. When testing is complete, the test is sent back to the company that publishes the CAT (CTB/McGraw Hill) for scoring, and then scoring information is returned to the school in the form of individual test reports.

The test report includes a scale score, which is the basic measurement of how a child performs on the assessment , and a national percentile (NP), which reflects the percentage of students in the national norm group who have scores below the student's score (e.g., an NP of 80 means that 80 percent of students scored lower than the student). The scale score may be derived one of two ways—a straight score determined by the total number of test items correct or through item-pattern scoring (also called item response theory, or IRT). Item-pattern scoring examines not only the number of correct responses, but also the difficulty level of the questions answered right and the interrelationship of the pattern of answers. Other scoring information may also be included in the test report depending on the scoring report format.

For students who are unfamiliar with the mechanics of taking a standardized test, a practice test session given by a teacher shortly before the CAT testing session begins may be appropriate. Because the CAT is designed to be a measurement of a child's current educational achievement level, the test publisher recommends that no pre-test coaching or test study programs be used.

Parental concerns


Norms —A fixed or ideal standard; a normative or mean score for a particular age group.

Representative sample —A random sample of people that adequately represents the test-taking population in age, gender, race, and socioeconomic standing.

Standardization —The process of determining established norms and procedures for a test to act as a standard reference point for future test results.


CTB/McGraw Hill. Terranova, 2nd ed. (California Achievement Tests, 6th ed.) Available online at

Harris, Joseph. What Every Parent Needs to Know About Standardized Tests. New York: McGraw-Hill, 2001.

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