What does standard deviation measure in the context of test scores?

Standard deviation is a statistical measure that quantifies the amount of variation or dispersion in a set of data points, such as test scores. In the context of test scores, it provides insight into how much individual scores deviate from the average score (mean) of the group. A low standard deviation indicates that the scores are closely clustered around the mean, suggesting that most students performed similarly. Conversely, a high standard deviation indicates that the scores are spread out over a wider range, reflecting greater variability in student performance.

Understanding standard deviation is crucial for teachers as it helps them recognize how diverse their students' abilities and knowledge levels may be, allowing them to tailor instruction to meet varied educational needs.