The table below is intended for general usage by health care providers and the general public. Psychologists commonly use these scores when describing test score results. For example, you may have heard of someone having an IQ score of 100. This is based on the column labeled standard score. Z-scores and scaled scores express the same thing that standard scores do, but do so based on a different numerical system.
Perhaps the most useful column for the average person to look at is the percentile column. The percentile rank allows you to determine an individual's position in relation to a sample of other individuals. More specifically, the percentile rank is the point in a distribution at or below which the scores of a given percentage of individuals fall. For example, a person with an IQ score of 120 (and a percentile rank of 91) has scored as well or better than 91 percent of people in the normal sample. For other measurements, please visit the MedFriendly Measurements section.