What does SEM stand for in the context of reliability?

In the context of reliability, SEM stands for Standard Error of Measurement. This term refers to the margin of error associated with an individual's observed score on a test due to the inherent variability in the measurement process. Essentially, it quantifies how much we can expect a person's score to fluctuate if they were to take the same test multiple times under similar conditions. Lower SEM values indicate more precise measurements, suggesting that the test produces results that are closer to the true score of the individual.

Understanding SEM is crucial in psychological testing and assessment because it helps practitioners interpret test scores more accurately. By taking SEM into account, school psychologists can provide a more nuanced understanding of a student’s abilities, thereby ensuring that any decisions made (such as educational placements or interventions) are well-informed and grounded in statistical evidence.