# Group Method of Data Handling
**Domain:** Machine Learning / Systems Identification / Cybernetics
**Doc Type:** Technical Method Node
**Maturity:** Historical
## Definition
The **Group Method of Data Handling**, or **GMDH**, is a family of self-organizing modeling procedures developed by [[wiki/Alexey Ivakhnenko|Alexey Ivakhnenko]]. Candidate combinations of input variables are generated in layers, fitted to data and selected according to external performance criteria.
## Historical Significance
GMDH joined a learned multilayer architecture with a separate testing set and structural selection. Ivakhnenko described this as heuristic self-organization and decision regularization.
## See Also
[[wiki/Held-Out Validation|Held-Out Validation]], [[wiki/Overfitting|Overfitting]], [[wiki/Artificial Neural Networks|Artificial Neural Networks]]