Outlier Detection

Consider the student exam scores scenario which contains some outliers

IQR method

• This method identifies outliers based on the quartiles of the data.

• It is more resistant to outliers than the mean-based methods like Z-score, making it better suited for skewed data like exam scores where a few high scores can significantly impact the mean.

Z-score method

• This method identifies outliers based on their standard deviation from the mean.

• However, it can be influenced by outliers itself, leading to inaccurate outlier detection when the data is skewed.

• In this scenario, the presence of a few high scores can inflate the standard deviation, potentially masking other outliers or misidentifying valid data points as outliers.