Meaning & use
standard deviation
Last updated
Meaning
nouncountable
A number that shows how much the values in a set of data differ from the average value.
Grammar: Countable: you can say 'a standard deviation' or 'the standard deviation is 2.5'.
Patterns
- the standard deviation of something
- a high/low standard deviation
- calculate/find the standard deviation
The standard deviation of the test scores was 12, meaning the scores were quite spread out.
If the standard deviation is small, most values are close to the average.
We calculated the standard deviation to see how consistent the results were.
Word forms
| plural | standard deviations |
|---|
Common combinations
- calculate the standard deviation
- You can calculate the standard deviation using a spreadsheet function.
- a large standard deviation
- A large standard deviation indicates that the data points are widely spread.
- a small standard deviation
- A small standard deviation means the data is clustered around the mean.
- the standard deviation of the sample
- The standard deviation of the sample was 3.2.
Synonyms and how they differ
Word family
- standardize verb
- To adjust values so they can be compared, often using the standard deviation.
Commonly confused: standard deviation or mean? standard deviation or variance?
standard deviation vs mean
The mean is the average value, while standard deviation measures how far values are from that average.
standard deviation vs variance
Variance is the square of the standard deviation; it is another measure of spread but in squared units.
Practice
A set of data has a mean of 50 and a standard deviation of 5. What does this tell you?
Choose one answer.
A small standard deviation (5) relative to the mean (50) indicates that values cluster near the mean. A large standard deviation would mean values are more spread out.
Make it your own
Write a sentence using “standard deviation”, then check it and compare it with the examples above.