Grid Search
Grid search tries all combinations of parameter values.
GridSearchCV
GridSearchCV(model, param_grid, cv=5). param_grid is dict of parameters to try.
cv determines cross-validation folds. Scoring metric defaults to accuracy.
Best parameters: grid_search.best_params_. Best score: grid_search.best_score_.
Random Search
RandomizedSearchCV samples parameter combinations. More efficient for large spaces.
n_iter controls number of combinations. random_state ensures reproducibility.
Key Takeaways
- Grid search exhaustively tries all combinations
- Random search is more efficient for large spaces
- Cross-validation guides parameter selection