# Reduced-Order Modeling
**Domain:** Austin Research / Concepts
**Doc Type:** Corpus analysis
**Source basis:** Supplied research cluster with linked references; see the [[wiki/Austin Research Evidence Map|evidence map]] for verification scope.
**Reduced-Order Modeling** constructs a lower-cost representation of a more expensive system or simulation while retaining behavior important to a specified task. It matters when a full calculation cannot finish within the time available for a decision.
[[wiki/Tan Bui-Thanh|Tan Bui-Thanh]]’s [[wiki/Defense Threat Reduction Agency|DTRA]]-supported radiation-effects work is a concrete Austin example. The desired prediction must retain useful accuracy while becoming fast enough for timely analysis. Oden’s digital-twin research combines related reduction methods with new observations and uncertainty estimates.
Reduction creates a fidelity–cost tradeoff. Conditions omitted from the reduced model can become decisive outside its validated range. Model reduction and VVUQ therefore work together: one improves feasibility, the other helps determine whether the resulting prediction remains trustworthy.
## Connected entries
[[wiki/Tan Bui-Thanh|Tan Bui-Thanh]] · [[wiki/PHOENICS|PHOENICS]] · [[wiki/PECOS|PECOS]] · [[wiki/Verification Validation and Uncertainty Quantification|Verification Validation and Uncertainty Quantification]] · [[wiki/Digital Twin|Digital Twin]] · [[wiki/Scientific Machine Learning|Scientific Machine Learning]] · [[wiki/Karen Willcox|Karen Willcox]] · [[wiki/Predictive Science|Predictive Science]]
## Sources and corpus context
- [[research/The Austin Executable Loop|The Austin Executable Loop — master document]]
- [Probabilistic and High Order Inference, Computation, Estimation, and Simulation](https://oden.utexas.edu/research/centers-and-groups/probabilistic-high-order-inference-computation-estimation-and-simulation/)
- [Minimizing Uncertainty in the Uncertain World of Defense, Energy](https://oden.utexas.edu/news-and-events/news/minimizing-uncertainty-in-uncertain-world-of-defense-energy/)
- [Scientific Machine Learning and Data-Driven Model Reduction for a Predictive Digital Twin](https://kiwi.oden.utexas.edu/research/digital-twin)
**Cluster:** [[wiki/Austin Executable Loop|Austin Executable Loop]] · [[wiki/Austin Research Evidence Map|Austin Research Evidence Map]]