What is meant by a "measure of dispersion" in statistics?

A measure of dispersion in statistics refers to a numerical value that indicates the extent to which data points in a dataset are spread out or clustered together. This concept is crucial for understanding the variability within a dataset. For instance, incorporating measures of dispersion such as range, variance, and standard deviation helps identify how much individual scores vary from the overall mean or median. If the dispersion is low, the data points are close to the average, whereas high dispersion signals that the data points are more widely distributed across a range.

In contrast, assessing central tendency focuses on summarizing a dataset by identifying a single value (like the mean or median) that represents the entire set, while determining frequency revolves around counting how often each score occurs. Calculating the median specifically pinpoints the middle value of a sorted dataset and does not address the overall spread of values. Thus, understanding measures of dispersion provides deeper insights into the characteristics and spread of data beyond just its central tendency.