optimal design of experiments
**Optimal Design of Experiments** is the **construction of experimental designs that optimize a specific statistical criterion** — using mathematical optimization to find the best possible set of experiments for a given model, constraints, and design size, rather than relying on classical factorial templates.
**Key Optimality Criteria**
- **D-Optimal**: Maximizes the determinant of $X^TX$ — minimizes the volume of the parameter confidence ellipsoid.
- **A-Optimal**: Minimizes the average variance of parameter estimates.
- **I-Optimal**: Minimizes the average prediction variance across the design space.
- **G-Optimal**: Minimizes the maximum prediction variance.
**Why It Matters**
- **Irregular Regions**: Works for constrained, non-rectangular parameter spaces where classical designs don't fit.
- **Custom Models**: Can design experiments for any specified model (non-standard terms, mixture models).
- **Fewer Runs**: Often achieves the same statistical power with fewer experiments than classical designs.
**Optimal DOE** is **custom-tailored experiments** — using math to design the statistically best possible experiment for your specific situation.