Achievement tests are standardized norm-referenced assessments that measure the examinee’s level of knowledge and skill. They can be administered individually or as a group. A good test must be objective and free of personal errors and biases.
A high score on an achievement test indicates that the examinee has mastered a grade-level topic and is ready to move on. However, low scores can indicate that the examinee is not ready for advancement or should receive additional training.
The California Achievement Test (CAT) is one of the most widely used standardized tests for children in kindergarten through grade 12. It is often used to determine whether a child should advance to a higher grade level and is also used by schools as part of state testing programs. The CAT is often administered to students in grades 3 through 7 as part of the STAR program.
Depending on the subject, the CAT is normed by comparing a student’s score to that of students in a nationally representative group. The resulting scores may be reported as either a scale score or percentile. A percentile measurement indicates how many students scored lower than the student on the assessment. Scale scores may be calculated in different ways, such as through item-pattern scoring, which examines the pattern of questions answered correctly and their difficulty levels.
While the CAT is commonly associated with traditional schooling, it is frequently used by homeschoolers as a way to assess their children’s progress. Homeschooling families must by law administer a nationally standardized test to each student annually, until they graduate high school.
The Wechsler Individual Achievement Test (WIAT) is a comprehensive individually administered assessment that measures academic abilities. The WIAT is often used to assess students with learning disabilities and to identify giftedness. It measures verbal, reading, and mathematical skills and consists of 16 subtests. Each of these subtests contributes to a different domain score.
The WIAT’s first subtest, Oral Language, measures the ability to listen and understand information presented orally. It also tests a person’s vocabulary and grammar. The second test is Reading Comprehension and Basic Reading, which measure a person’s ability to read passages and understand them. The third test is Word Reading, which measures a person’s ability to decode and pronounce single-word words. Poor performance on this test could suggest dyslexia.
The WIAT is a commercially available standardized test that produces subtest and cluster or composite standard scores in the form of percentile ranks, stanines, and normal curve equivalent scores. It also yields a total achievement index in the form of FSIQ. Convergent validity between the WIAT and Woodcock-Johnson III Tests of Achievement – Form A is established in both normative and clinical samples.