Z-Score is?

Z-Score is?

• A. A raw score on a 0-1 scale.
• B. Percentage of scores above a given score.
• C. How many standard deviations above the mean.
• D. The distance a raw score is from the mean when measured in units of standard deviation.

Answer: (D)

Z-scores tell you how far a score is from the average in units of standard deviation. They standardize different measurements so you can compare scores across different tests. The best description is that a z-score is the distance a raw score is from the mean when measured in units of standard deviation. This captures both how far and in which direction the score lies from the mean: z can be positive if above the mean or negative if below. A raw score on a 0–1 scale isn’t a z-score, and saying it’s only about how many standard deviations above the mean ignores scores below the mean. Percent above a threshold describes a percentile, not a z-score.

Z-scores tell you how far a score is from the average in units of standard deviation. They standardize different measurements so you can compare scores across different tests. The best description is that a z-score is the distance a raw score is from the mean when measured in units of standard deviation. This captures both how far and in which direction the score lies from the mean: z can be positive if above the mean or negative if below. A raw score on a 0–1 scale isn’t a z-score, and saying it’s only about how many standard deviations above the mean ignores scores below the mean. Percent above a threshold describes a percentile, not a z-score.