# What is Bayesian Optimization? Definition & Technical Mechanics

> **Source:** [SPIDITS AI AI Glossary](https://spidits.com/ai-glossary)  
> **Category:** Mathematical Foundations  
> **Canonical Citation:** [https://spidits.com/ai-glossary/bayesian-optimization](https://spidits.com/ai-glossary/bayesian-optimization)

## Definition
Bayesian Optimization is a sequential design strategy for global optimization of black-box functions. It is widely used in machine learning to tune hyperparameters, particularly when evaluating the target function is computationally expensive.

## Architectural Mechanics & Deep Dive
Bayesian optimization is a sequential design strategy for global optimization of black-box functions that are computationally expensive to evaluate. It is widely used in machine learning for hyperparameter tuning. By building a probabilistic model of the objective function (typically using Gaussian Processes) and utilizing an acquisition function to balance exploration and exploitation, it efficiently locates optimal hyperparameters with minimal function evaluations.

## Industry Applications & Real-World Use Cases
Hyperparameter tuning, automated machine learning (AutoML), and experimental design.

## Frequently Asked Questions

### How does Bayesian optimization work?
It builds a probabilistic model (usually a Gaussian Process) of the objective function and uses an acquisition function to decide where to sample next, balancing exploration and exploitation.

### Why is Bayesian optimization preferred over grid search?
Because it keeps track of past evaluation results to make informed decisions about the next hyperparameter set to test, finding optimal values in far fewer iterations.

## Related Terminology
- [hyperparameter](https://spidits.com/ai-glossary/hyperparameter)
- [gradient-descent](https://spidits.com/ai-glossary/gradient-descent)
- [validation-data](https://spidits.com/ai-glossary/validation-data)

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*From the SPIDITS AI Knowledge Base (336+ terms indexed). Explore full technical definitions: [https://spidits.com/ai-glossary](https://spidits.com/ai-glossary)*