What is an Achievement Test?

Achievement tests are designed to measure a student's performance in specific academic areas such as reading comprehension, written or oral expression, and mathematical computations. An achievement test may be designed to be given to a large group of students at one time, or it may be intended for more individualized testing. Schools may make use of large-scale achievement tests in order to evaluate the overall success of the school in delivering the curriculum such that students are learning the necessary skills for their grade level. Tests often used for this sort of assessment include the Stanford Achievement Tests, California Achievement Tests, the Iowa Tests of Basic Skills, the Canadian Achievement Tests and the Canadian Tests of Basic Skills.

Examples of achievement tests used in small group or individualized settings include the Wechsler Individual Achievement Test, the Kaufman Test of Educational Achievement, and the Peabody Individual Achievement Test. These tests may be used when a learning disability is suspected, in order to measure the academic progress of a homeschooled student, or to determine placement in school programs for special populations such as gifted students.

What achievement tests do not measure
Achievement tests are not intended to measure raw intelligence or aptitude. An achievement test will not measure a student's intelligence quotient (IQ) nor will it predict how well a student is likely to do in a specific academic area. An achievement test can be used side by side with an IQ test such as the Wechsler Intelligence Scale for Children, or with an aptitude test like the Canadian Test of Cognitive Skills, to detect differences between raw potential and actual performance. Such discrepancies may be due to specific learning disabilities, which can be confirmed with further testing, or they may indicate a need to offer learning activities better suited to the student's interests and abilities.

Scoring of achievement tests
Achievement tests are standardized test that measure how well a student performs in comparison to large groups of students at the same age or grade level who have also taken that test. Scores can be expressed in terms of a grade level, or as a percentile. A grade level score is expressed as a decimal, for example a score of 3.2 indicates achievement around the second month of the third grade. A score of 7.9 indicates achievement at the end of the seventh grade.

A student's percentile score shows where he fits on a bell curve of students at the same age or grade level. If he scores in the 53rd percentile, he scored better than 53 percent of peers who took the test. If he scores in the 97th percentile, he performed better than 97 percent of his peers. A score around 50 is average, and a large number of students will be clustered around this level. Scores below the 25th or above the 75th percentile will be more rare. They may be signs of impairment or of giftedness, but further testing will be required to explore these possibilities.

Achievement tests in a homeschooling environment
Homeschoolers may find that achievement tests are a useful tool for planning and evaluating their educational program. Neuropsychologist Suzanne Day recommends achievement tests before beginning to homeschool in order to establish a baseline for academic performance, especially if there are suspected learning difficulties. This allows parents to arrange for further testing as needed. Identifying specific strengths and weaknesses gives parents the ability to adapt the curriculum to better suit their children. In the case of parents who must report the child's progress to the educational authority, it can be helpful to have a baseline set at the beginning of the year, with which to compare the child's end of the year achievement. If the child is below grade level in any subject area, but has made progress equivalent to one grade level during the year, parents can be assured that the child is making headway and will not fall into doubting their ability to homeschool.

Large scale achievement tests are generally only available to schools, but some suppliers will sell them to families who homeschool. The test is written at home following the directions, and then all the materials are returned to the supplier for scoring. Test scores are sent through the mail. Parents have the option of hiring a teacher or invigilator if they need to have more formal proof of objective assessment, but they are not obliged to do so. Testing in this manner is economical, and it can be less stressful for the students. Hiring an educational psychologist to conduct individual achievement tests is more expensive, but if learning difficulties are suspected this is one of the first steps towards a complete psycho-educational screening that will pinpoint issues such as dyslexia, ADHD or autism spectrum disorders.

Sources:
Suzanne Day, "Standardized achievement tests for home educators." Wise Choice Educational Services

Shirley M.R. Minster, M.S. Ed., "A Brief Discussion of Individual Achievement Tests." HomeEducator.com

"What Parents Should Know About Test Types." Center for the Assessment and Evaluation of Student Learning