★ = best found point. Bayesian opt concentrates evaluations near the optimum intelligently.
Model Selection & Hyperparameter Search - Interactive Visualization
Hyperparameter tuning is one of the highest-leverage activities in applied ML. Grid search exhaustively evaluates every combination - wasteful but thorough. Random search samples hyperparameters independently and is often just as good with far fewer evaluations. Bayesian optimization uses a surrogate model (usually a Gaussian process) to model the validation metric surface and focus evaluations on the most promising regions.
Watch grid search exhaustively fill the hyperparameter grid vs random search scattering evaluations across the same space
See why random search works: if only 2 of 10 hyperparameters matter, random search covers those dimensions much more densely
Observe Bayesian optimization focus evaluations on regions near the current best - each evaluation informs the next
Understand the acquisition function: expected improvement decides where to evaluate next, trading exploration vs exploitation
Learn nested cross-validation: the only unbiased way to both tune hyperparameters and estimate generalization error
Part of the EngineersOfAI Interactive 3D - free interactive visualizations covering every major concept in machine learning and AI engineering. Hover any element for a plain-English explanation. No code required.