A raw score is a place on a ruler; a z-score is a place in a crowd. Standardizing turns “82” into “+1.1,” which turns into, “about the 86th percentile… ahead of most peers.” That’s communication. Use z-scores to compare across different scales (points vs minutes vs questions right) and to spot the unusual without guessing. But remember: standardization borrows the shape of your distribution. If the shape is weird, say so. Z is a translator, not a truth serum.
