I was reading the following link: http://machinelearningmastery.com/how-to-identify-outliers-in-your-data/
In the link they have made the following statement:
Outliers are extreme values that fall a long way outside of the other observations. For example, in a normal distribution, outliers may be values on the tails of the distribution.
Can we say that the data points that lie outside the 2nd or 3rd standard deviation is an outlier? Just wanted to know can I apply this technique in outlier detection?