skewness
Học thuậtThân thiện
Definition
Noun: * An oblique or slanting asymmetry; lack of symmetry in a probability distribution. In statistics, skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. It describes whether the data points are concentrated more on one side of the mean than the other.
Usage
- Skewness is a statistical concept used to quantify the degree of asymmetry in a dataset's distribution.
- A distribution with zero skewness is symmetric.
- Positive skewness (right-skewed) indicates a longer tail on the right side, meaning the mass of the distribution is concentrated on the left.
- Negative skewness (left-skewed) indicates a longer tail on the left side, meaning the mass of the distribution is concentrated on the right.
Examples
- Noun:
- The skewness of the income data was positive, indicating a few very high incomes.
- A normal distribution has a skewness of zero.
- The analyst calculated the skewness to understand the bias in the sample.
Advanced Usage
- "Measure of skewness": A specific formula or statistic (like Pearson's moment coefficient of skewness) used to calculate the degree of asymmetry.
- The measure of skewness confirmed the visual impression from the histogram.
- "Coefficient of skewness": The numerical value resulting from a skewness calculation.
- A coefficient of skewness greater than +1 indicates a highly right-skewed distribution.
Variants and Related Words
- Skewed (adj): Not symmetrical; distorted or biased.
- The results were skewed by several extreme outliers.
- Skew (verb): To cause something to be not straight or symmetrical; to distort or bias.
- A small sample size can skew the findings of the study.
Synonyms
- Asymmetry
- Lopsidedness
- Imbalance (in a statistical context)
Antonyms
- Symmetry
Noun
- an oblique or slanting asymmetry