- Skewed Statistics: Means and standard deviations can be distorted.
- Misleading Visualizations: Outliers affect the readability of charts and graphs.
- Model Performance Issues: In machine learning, outliers can cause models to misfit data, leading to poor generalization.
- There are several ways to detect outliers, each with its own strengths and limitations.
- Z-score method
- IQR (Interquartile Range) method
- Robust methods
| Method | Best For | Limitations | Suitable Distributions |
|---|---|---|---|
| Z-score | Normally distributed data | Sensitive to extreme values | Normal |
| IQR | Skewed distributions | May not work well for small datasets | Skewed or normal |
| MAD | Skewed or non-normal data | Interpretation can be complex | Highly skewed |