What problem does it solve? Applying classical machine learning correctly requires choosing the right algorithm, preprocessing data without leakage, tuning hyperparameters, and evaluating models rigorously. This Skill provides structured guidance and reference documentation for doing all of this with scikit-learn, avoiding common mistakes like data leakage and poor metric selection. ## Core Features & Use Cases - Supervised and Unsupervised Learning: Guidance for classification, regression, clustering, and dimensionality reduction algorithms including Random Forest, Gradient Boosting, SVM, K-Means, DBSCAN, and PCA. - Pipelines and Preprocessing: Patterns for ColumnTransformer, scaling, encoding, and imputation that prevent data leakage and keep workflows reproducible. - Model Evaluation and Tuning: Cross-validation strategies, GridSearchCV and RandomizedSearchCV, and metric selection for balanced and imbalanced data. - Use Case: Given a CSV with mixed numeric and categorical columns, build a full pipeline that imputes missing values, encodes categories, tunes a Gradient Boosting classifier with grid search, and reports precision, recall, and ROC AUC on a held-out test set. ## Quick Start Use the scikit-learn skill to build a classification pipeline with preprocessing and cross-validated hyperparameter tuning for my dataset.