The norm-referenced score scale used by the National Foundation for Educational Research (NFER) is described. The usefulness of standardized scores is explained by a simple numerical example, and the formulas and computations are shown for calculating a mean, a standard deviation, and a deviation or z score. The need for a representative sample is explained and the normal distribution curve is described. Finally, NFER standardized scores and percentiles are explained, tabulated and presented graphically. (CTM)