Skewness and Kurtosis

Skewness

The coefficient of Skewness is a measure for the degree of symmetry in the variable distribution.

Negatively skewed distribution or Skewed to the left Skewness <0		Normal distribution Symmetrical Skewness = 0		Positively skewed distribution or Skewed to the right Skewness > 0

Kurtosis

The coefficient of Kurtosis is a measure for the degree of peakedness/flatness in the variable distribution.

Platykurtic distribution Low degree of peakedness Kurtosis <0		Normal distribution Mesokurtic distribution Kurtosis = 0		Leptokurtic distribution High degree of peakedness Kurtosis > 0

Literature

• Sheskin DJ (2011) Handbook of parametric and nonparametric statistical procedures. 5th ed. Boca Raton: Chapman & Hall /CRC.

See also

• Summary statistics
• Reference interval
• Tests for Normal distribution

External links

• Skewness on Wikipedia.
• Kurtosis on Wikipedia.