What does the standard deviation most commonly measure?

The standard deviation is a key statistical measure that quantifies the amount of variation or dispersion in a set of data values. When applied in the context of mass appraising, understanding the spread of property values is crucial for accurate assessments.

Specifically, a low standard deviation indicates that the data points tend to be close to the mean (average), while a high standard deviation suggests that the data points are spread out over a wider range of values. This is critical in mass appraisal as it provides insight into how property values fluctuate within a given area, helping assessors determine fair market values and ensuring equity in property taxation.

In contrast, the concepts of central tendency, range of values, and frequency of occurrence describe different aspects of data. Central tendency refers to measures like the mean or median, which summarize the dataset with a single value. The range of values reflects only the difference between the maximum and minimum values, and frequency of occurrence pertains to how often certain values appear within the data set. None of these fully capture the concept of dispersion that standard deviation embodies. Thus, the correct recognition of standard deviation as a measure of dispersion reflects its critical role in statistical analysis and mass appraising.