coefficient of variation: meaning, definition, pronunciation and examples
C2Technical / Academic / Scientific
Quick answer
What does “coefficient of variation” mean?
A statistical measure that expresses the standard deviation as a percentage of the mean, used to quantify relative variability.
Audio
Pronunciation
Definition
Meaning and Definition
A statistical measure that expresses the standard deviation as a percentage of the mean, used to quantify relative variability.
A normalized measure of dispersion of a probability distribution or data set, allowing comparison of variability between data sets with different units or vastly different means.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or semantic differences. The abbreviation 'CV' is used in both variants, though 'coefficient of variation' is the standard full term. Punctuation in the abbreviation may differ (e.g., c.v. vs. CV).
Connotations
Identical technical connotations.
Frequency
Identical frequency within technical fields such as statistics, finance, engineering, and laboratory sciences. Rare to non-existent in general discourse in both variants.
Grammar
How to Use “coefficient of variation” in a Sentence
The coefficient of variation [is/was] [calculated] at 15%.A [high/low] coefficient of variation indicates...We [used/computed/compared] the coefficient of variation to...The [adjective] coefficient of variation [verb]...CV = (σ/μ) * 100%Vocabulary
Collocations
Examples
Examples of “coefficient of variation” in a Sentence
verb
British English
- The data were analysed to coefficient of variation.
American English
- The data were analyzed to coefficient of variation.
adjective
British English
- The coefficient-of-variation analysis proved insightful.
American English
- The coefficient-of-variation analysis proved insightful.
Usage
Meaning in Context
Business
Used in finance and risk management to compare the risk (volatility) per unit of return across different investments. Example: 'The fund with the lower coefficient of variation offers better risk-adjusted returns.'
Academic
Standard term in statistics, experimental sciences (e.g., biology, chemistry), engineering, and psychology for reporting the consistency or precision of measurements relative to their average size.
Everyday
Extremely rare. Might be paraphrased as 'how spread out the numbers are compared to their average'.
Technical
Primary context. Used in quality control, meteorology, pharmacology, and any field requiring comparison of variability across datasets with different means or units.
Vocabulary
Synonyms of “coefficient of variation”
Strong
Neutral
Weak
Vocabulary
Antonyms of “coefficient of variation”
Watch out
Common Mistakes When Using “coefficient of variation”
- Using it for data on an interval scale (e.g., temperature in Celsius) where the mean can be zero or negative, rendering the CV meaningless.
- Forgetting to multiply by 100% when expressing it as a percentage.
- Confusing it with the variance or standard deviation, which are absolute measures.
- Comparing CVs when means are very close to zero, which inflates the CV.
FAQ
Frequently Asked Questions
There is no universal threshold. It depends entirely on the field and context. In analytical chemistry, a CV < 5% might be excellent, while in some biological assays, up to 20-30% might be expected. It is used for comparison, not absolute judgment.
Yes. A CV > 100% occurs when the standard deviation is larger than the mean. This is common in data with a very low mean and positive skew, such as waiting times for rare events or certain ecological count data.
The main advantage is that it is a dimensionless, scale-free measure. This allows for direct comparison of variability between datasets that have different units of measurement or drastically different average values, which the standard deviation cannot do.
Essentially, yes. RSD is typically the coefficient of variation expressed as a percentage. The terms are often used interchangeably in many scientific fields.
A statistical measure that expresses the standard deviation as a percentage of the mean, used to quantify relative variability.
Coefficient of variation is usually technical / academic / scientific in register.
Coefficient of variation: in British English it is pronounced /ˌkəʊɪˌfɪʃ(ə)nt əv ˌveəriˈeɪʃ(ə)n/, and in American English it is pronounced /ˌkoʊəˌfɪʃənt əv ˌveriˈeɪʃən/ /ˌkoʊəˌfɪʃənt əv ˌværiˈeɪʃən/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “No idioms exist for this technical term.”
Learning
Memory Aids
Mnemonic
Think: CV = 'Compare Variability'. Your CV (résumé) compares you to others; the statistical CV compares variability relative to the mean.
Conceptual Metaphor
VARIABILITY IS A RELATIVE MEASURE (as opposed to an absolute one).
Practice
Quiz
In which situation is the coefficient of variation (CV) most appropriately used?