Which option correctly defines Standard Deviation?

Which option correctly defines Standard Deviation?

• A. A fixed scale used to measure performance
• B. The mathematical calculation that indicates the variability in comparison with the average
• C. The average score across all questions
• D. A process for evaluating teaching effectiveness

Answer: (B)

Standard deviation describes how spread out a set of scores is around the average. It’s a mathematical calculation that takes each score’s distance from the mean, squares those distances, averages them, and then takes the square root. This result shows the variability in a data set: a small value means most scores cluster near the average, while a large value indicates bigger differences from the mean. This is exactly what’s being captured when we talk about variability relative to the average. It’s not a fixed scale, not the average itself, and not a process for evaluating teaching—it's the measure of how much scores vary around the mean.

Standard deviation describes how spread out a set of scores is around the average. It’s a mathematical calculation that takes each score’s distance from the mean, squares those distances, averages them, and then takes the square root. This result shows the variability in a data set: a small value means most scores cluster near the average, while a large value indicates bigger differences from the mean. This is exactly what’s being captured when we talk about variability relative to the average. It’s not a fixed scale, not the average itself, and not a process for evaluating teaching—it's the measure of how much scores vary around the mean.