What does the standard error of measurement represent in test scores?

• A. The expected range of an observed score due to measurement error
• B. The maximum score possible on the test
• C. The average score of the test
• D. The correlation between test and criterion

Answer: (A)

The standard error of measurement tells you how precise a single test score is by capturing the amount of error that can affect what you observe. It represents the typical range within which the observed score would fall around a person’s true ability due to measurement imperfections. In other words, if a person’s true score is T, the score you see on the test is likely to lie within roughly one SEM above or below T. The smaller the SEM, the more precise the measurement, because reliability increases as error decreases (SEM is related to reliability through the formula SEM = SD × sqrt(1 − reliability)). This concept helps you interpret scores by framing observed results as estimates of the true ability, often using confidence intervals around the observed score. It’s not about the maximum possible score, the average score, or the relationship to an external criterion, which is why the standard error of measurement is described as the expected range of an observed score due to measurement error.