First, those scores below the mean (such as 8 and 10) have negative z scores, and those scores above the mean (such as 13 and 14) have positive z scores. Second, positive z scores always fall to the right of the mean and are in the upper half of the distribution. And negative z scores always fall to the left of the mean and are in the lower half of the distribution. Third, when we talk about a score being located 1 standard deviation above the mean, it’s the same as saying that the score is a z score of 1. For our purposes, when comparing scores across distributions, z scores and standard
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