Range is a term used to describe the variability of values observed in a data set. It is a measure of dispersion or spread in the data and is often used to refer to the difference between the highest and lowest values in a given set of observations (Mardia, Kent & Bibby, 1979). Range is often used in combination with other measures of dispersion, such as variance and standard deviation, to gain a better understanding of the data and to compare different data sets.

Range is a simple measure of dispersion, and it is easy to calculate. To calculate the range, the highest and lowest values in a set of observations are identified, and the difference between them is calculated. For example, if the five observations in a data set are 2, 4, 6, 8, and 10, then the highest value is 10 and the lowest value is 2, and the range is 8 (10 – 2= 8).

Range is a useful measure of dispersion, but it has some limitations. One limitation is that it is not sensitive to subtle differences in the data, and it is not a particularly good measure of central tendency. Range is also affected by extreme values, which can distort the data. For example, if one outlier (an observation that is much higher or lower than the rest of the data) is included in the data set, the range is likely to be much higher than it would be otherwise.

In conclusion, range is a simple measure of dispersion, and it is easy to calculate. Range is often used in combination with other measures of dispersion, such as variance and standard deviation, to gain a better understanding of the data and to compare different data sets. However, range has some limitations, and it is not a particularly good measure of central tendency.

References

Mardia, K. V., Kent, J. T., & Bibby, J. M. (1979). Multivariate analysis. London: Academic Press.