Standard deviation describes what aspect of a data set?

• A. The spread of the scores around the mean.
• B. The central tendency of scores.
• C. The highest score in the distribution.
• D. The rate of change over time.

Answer: (A)

Standard deviation describes how much the scores in a data set spread out around the average. It’s a measure of variability or dispersion, showing how far individual scores tend to deviate from the mean. A small standard deviation means scores cluster near the mean; a large one indicates more variability in the data. It’s not about the central value itself (that’s the mean/median/mode), not about the highest score, and not about change over time. Expressed in the same units as the data, it provides an intuitive sense of how much the data vary.