What does variance mean?

What does variance mean?

• A. defines the distribution of performance around the mean.
• B. describes central tendency.
• C. is the same as standard deviation.
• D. measures sampling error.

Answer: (A)

Variance captures how far individual scores tend to be from the average score, by taking the average of the squared differences from the mean. This describes the spread or dispersion of the distribution around the mean: small variance means scores cluster near the mean, large variance means they are more spread out. It’s different from describing the center itself (that’s central tendency, like the mean). It’s also not the same as the standard deviation, which is the square root of the variance and shares the same units as the data. And variance isn’t the same thing as sampling error, which is about how a sample statistic may differ from the true population value due to sampling. In short, variance defines the spread of performance around the mean.

Variance captures how far individual scores tend to be from the average score, by taking the average of the squared differences from the mean. This describes the spread or dispersion of the distribution around the mean: small variance means scores cluster near the mean, large variance means they are more spread out. It’s different from describing the center itself (that’s central tendency, like the mean). It’s also not the same as the standard deviation, which is the square root of the variance and shares the same units as the data. And variance isn’t the same thing as sampling error, which is about how a sample statistic may differ from the true population value due to sampling. In short, variance defines the spread of performance around the mean.