ERIC Number: ED445089
Record Type: Non-Journal
Publication Date: 2000-Feb
Reference Count: N/A
Measurement Error. For Good Measure....
Johnson, Stephen; Dulaney, Chuck; Banks, Karen
No test, however well designed, can measure a student's true achievement because numerous factors interfere with the ability to measure achievement. These factors are sources of measurement error, and the goal in creating tests is to have as little measurement error as possible. Error can result from the test design, factors related to individual students, the testing situation, and many other sources. Some errors are test-specific. The Standard Error of Measurement concept is used to determine the range of certainty around a student's reported score. It estimates the range of scores individual students might get if they were to take the same test over and over (assuming no benefits from the repeated practice). To estimate the error for a score reported for a group, another statistic, the Standard Error of the Mean, is used. A table shows the standard error of the mean for the North Carolina End-of-Grade reading tests. It is possible to be much more confident about the interpretation of the scores of groups of students on the end-of-grade tests than it is to be confident about the score of an individual student. Formulas are given for the Standard Error of Measurement and the Standard Error of the Mean. (SLD)
Publication Type: Reports - Descriptive
Education Level: N/A
Authoring Institution: Wake County Public School System, Raleigh, NC. Dept. of Evaluation and Research.