Range and standard deviation are statistical measures used to describe variability or dispersion in a set of data. Both help in understanding how data values are spread, but they differ in calculation, interpretation, and usefulness in research and nursing education. Range is the difference between the highest value and the lowest value in a data set. It is the simplest measure of dispersion. It gives a quick idea about the spread of data. The formula for range is: Range = Highest value – Lowest value Standard deviation is a statistical measure that shows how much the individual observations deviate from the mean or average of the data. It is considered a more reliable and accurate measure of variability because it includes all values in the calculation. The major differences between range and standard deviation are as follows: 1. Meaning: Range measures the total spread between the maximum and minimum values only. Standard deviation measures the average deviation of all observations from the mean. 2. Basis of Calculation: Range is calculated using only two values, the highest and the lowest values. Standard deviation is calculated using every observation in the data set. 3. Accuracy: Range is less accurate because it ignores most of