In recent years the testing of students has become increasingly important and a major component of American education. Examinations are being used to ensure accountability to school constituents as well as to assess the academic achievement of students. As a consequence, it has become essential that appropriate interpretation of test results takes place. The following provides answers to frequently asked questions (FAQs) regarding norm-referenced achievement tests.
What are norm-referenced achievement tests?
- Norm-referenced tests compare a person’s score to the scores of a group of people who have already taken the same exam called the “norming”group.
What is the purpose of norm-referenced achievement tests?
- The purpose is to assess student achievement by comparing one’s scores to others who have taken the same exam. The test does not provide information about what a student does or does not know but rather places students in “rank order”.
What does “norm-referenced” mean?
- A sample (subset) of the target student population (e.g. 5th graders) who has previously taken the test is used for comparison purposes. Testmakers create exams whose distribution of scores is graphically represented by a bell-shaped (“normal”) curve. The test design is such that most (5th grade) students will score near the middle, and only a few will score low (the left side of the curve) or high (the right side of the curve).
What other types of tests are there in addition to achievement tests?
- Other types of commonly used exams include aptitude tests (a measure of a student’s ability) and criterion-referenced tests (an assessment used to see whether students have mastered a certain body of knowledge).
What is a “percentile rank”?
- A percentile is a score that indicates the rank of a student compared to others using a hypothetical group of 100 students. For example, a percentile rank of 50% means that the student’s test performance equals or exceeds 50 out of 100 students taking the same exam; a percentile rank of 88% indicates that the student’s test performance equals or exceeds 88 out of 100 students taking the same exam. Note that percentile rank is not equivalent to percent. Typically in American schools a student scoring a 50% on a classroom exam indicates that the student got ½ of the exam questions correct earning him/her a failing grade.
What are the age/grade equivalent scores?
- Such scores indicate that a student has attained the same score (not skills) as an average student of that age/grade. For example, if a student obtains a grade-equivalent score of 6.8 on a mathematics test, this means that she obtained the same score as the typical student in the 8th month of the 6th grade. Note that this does not mean that the child is ready for the 6th grade! It simply means that an average 6th grader would have scored as well on the same test and that the child mastered the material very well.
How accurate are norm-referenced achievement test scores?
- All tests have “measurement error” and are not perfectly reliable. Sometimes results are reported in “bands” which show a range within which the student’s “true score” is likely to have fallen. For instance, a score of 73 may in actuality fall between 66 and 80 but could even be further off.
- There are many factors that can cause measurement error including an ill student, unfamiliarity with exam design, distractions during the exam, or a student simply having a “bad day”.
- The items on the exam are only a very small sample of the whole subject area. There are a very large number of questions that could be asked but generally there will only be a few dozen. With so few questions being asked a student getting even one more right or wrong can cause a big change in the student’s score.
- If one is disappointed in the results of a particular exam, retaking the exam can help give the student a clearer picture of what their “true score” is.
Most achievement exams are focused heavily on memorization and routine procedures. This means that they often do not provide a thorough assessment of problem-solving, decision-making, judgment, or understanding.