Coefficient of variation
Also called: CV · Topic: Geographical Data: Sources, Compilation and Processing · NCERT: Beyond NCERT
Meaning
The coefficient of variation (CV) measures how much values vary compared with their mean. CV = standard deviation ÷ mean × 100. Standard deviation is a measure of how far values spread from the mean. Because CV is a percentage, it can compare variability between data sets of different sizes or units. A high CV means the values change a lot from one observation to the next, so they are less dependable.
Example
India's rainfall CV is above 50% in western Rajasthan and Kutch (Gujarat), and below 25% on the west coast and in the north-east. So the driest areas also have the least dependable rain, which matters for drought-proofing and crop planning.
Don't confuse with
- Standard deviation: shows spread in the data's own units (such as mm), so it cannot fairly compare data sets with very different means.
Related concepts
- Measures of dispersion
- Range
- Mean deviation
- Standard deviation
- Measures of relationship
- Correlation coefficient