Z-score
Last updated
Last updated
Also known as standard score of an observation, this method assumes data follows a gaussian distribution.
It's a parametric method which indicates how many standard deviations an instance is from the sample’s mean.
The z-score of every data point is calculated using the formula: . It can be easily calculated using the method provided by sklearn.
Once every z-score is computed, outliers are detected given a threshold. It's usually set to: , or .