What does a standard deviation measure in a data set?

The standard deviation is a statistical measure that quantifies the amount of variation or dispersion in a set of data points. Specifically, it indicates how much individual data points differ from the mean (average) 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 the reliability and variability of a dataset, as it helps to assess the consistency of the measurements captured. This concept is fundamental in psychology research, where understanding the variation among responses can shed light on the different behaviors or traits being analyzed.