In statistics, what does standard deviation indicate?

Standard deviation is a key statistical measure that indicates the amount of variation or dispersion within a set of values. When we say that standard deviation measures the spread of a set of values from the mean, we are referring to how much individual data points deviate from the average value of the dataset. A low standard deviation means that the data points tend to be close to the mean, while a high standard deviation indicates that the data points are spread out over a wider range of values.

Understanding standard deviation is crucial for interpreting data because it provides insight into the consistency or variability of the dataset. Researchers and psychologists often rely on this measure to evaluate how much individual scores differ from the average, which can inform decisions based on the reliability and significance of the data. In the context of psychological testing or assessments, knowing the standard deviation helps to interpret the performance or behaviors of individuals in relation to the group mean.