Decision Tree
From IT위키
Decision Tree
A Decision Tree is a supervised learning algorithm used for both classification and regression tasks. It structures decisions as a tree-like model, where each internal node represents a test on a feature, each branch represents an outcome of that test, and each leaf node represents a class label or prediction. Decision Trees are highly interpretable and can work with both categorical and numerical data, making them widely applicable across various fields.
Key Concepts[edit | edit source]
- Node Splitting: The process of dividing data at each node based on a feature value that best separates the classes or reduces prediction error. Popular criteria for splitting include:
- Gini Impurity: Measures the likelihood of an incorrect classification by a randomly chosen element; lower values indicate better splits.
- Entropy: Quantifies data disorder, where a decrease in entropy signifies an increase in information gain.
- Recursive Partitioning: The tree is constructed by repeatedly splitting subsets of data at each node, creating branches until stopping criteria are met.
- Pruning: A technique for trimming the tree by removing nodes that offer minimal contribution to accuracy, which helps in reducing overfitting.
Common Applications[edit | edit source]
Decision Trees are used across industries due to their transparent and straightforward structure:
- Healthcare: Used for clinical decision-making and diagnosis, where interpretability is crucial for understanding factors influencing predictions.
- Finance: Applied in credit scoring, risk analysis, and fraud detection, providing clear decision paths for assessment.
- Marketing: Assists in customer segmentation and identifying factors leading to churn, allowing for targeted marketing strategies.
- Manufacturing: Used in quality control to detect defect patterns and in predictive maintenance to estimate equipment lifespan.
Strengths[edit | edit source]
- High Interpretability: The visual and rule-based nature of Decision Trees makes them easy to understand and communicate, even to non-technical stakeholders.
- Minimal Data Preparation: Unlike many models, Decision Trees do not require feature scaling or normalization, making them compatible with raw datasets.
- Versatile with Feature Types: Can handle both categorical and numerical data directly, offering flexibility in data preparation.
Limitations[edit | edit source]
- Prone to Overfitting: Decision Trees can grow overly complex, capturing noise in the training data, which impacts their ability to generalize.
- Instability with Small Variations: A slight change in data can lead to a completely different tree structure, affecting model consistency.
- Bias with Imbalanced Data: Without adjustment, Decision Trees may favor majority classes, leading to biased predictions in imbalanced datasets.
Techniques for Improved Performance[edit | edit source]
- Pruning: Reduces the tree size by cutting off non-informative branches, helping to prevent overfitting.
- Ensemble Methods: Combining Decision Trees in methods like Random Forests or Gradient Boosting reduces individual tree bias and improves accuracy.
- Hyperparameter Tuning: Adjusting parameters like maximum depth and minimum samples per leaf can help control tree growth and balance performance.