Outlier detection and removal are critical steps in data preprocessing for machine learning and data science. According to a recent survey, 90% of data scientists believe that identifying and handling outliers significantly improves the accuracy of their models. Outliers can skew results, leading to misleading insights. Techniques for outlier detection include statistical methods like the Z-score, where data points more than three standard deviations from the mean are often considered outliers. Another method is the Interquartile Range (IQR), where outliers are those below Q1 – 1.5 IQR or above Q3 + 1.5 IQR. Machine learning approaches like Isolation Forest and Local Outlier Factor (LOF) are also popular, with 70% of professionals using these methods. The choice of method depends on the dataset’s nature and the analysis’s goals.
Source: stackoverflow.com















