What is the significance of a T-score?

The significance of a T-score lies in its standardized distribution, which is specifically designed to have a mean of 50 and a standard deviation of 10. This standardization allows for easy interpretation of an individual’s score in relation to a normative population. A T-score tells us how many standard deviations a particular score is from the mean. For example, a T-score of 60 indicates that a score is one standard deviation above the average, while a score of 40 indicates one standard deviation below the average. This scoring system is particularly useful in psychological assessments as it allows clinicians and educators to gauge how an individual's performance compares to peers in a consistent manner.

In contrast to this, the other options provide incorrect or misleading information about T-scores. For example, a mean of 100 with a standard deviation of 10 typically describes IQ scores rather than T-scores. Moreover, while percentile ranks do provide information about relative standing within a population, T-scores do not represent this directly; instead, they provide a raw score transformed into a standardized format. Lastly, T-scores do not indicate that scores are always higher than the average, as they can be both above and below the mean depending on the individual's performance in the context of the normative data