# Stochastic Gradient Descent
**Domain:** Optimization / Machine Learning
**Doc Type:** Canonical Method Node
**Maturity:** Foundational
## Definition
**Stochastic gradient descent** updates model parameters using gradients estimated from individual examples or subsets of data rather than from the complete dataset at every step.
## Historical Context
[[wiki/Shun-Ichi Amari|Shun-Ichi Amari's]] 1967 probabilistic descent method is interpreted by [[wiki/Jürgen Schmidhuber|Jürgen Schmidhuber]] as an early stochastic-gradient procedure applicable to multilayer training. The attribution remains distinct from the paper's own vocabulary.
## Technical Context
Stochastic estimates reduce the cost of each update and introduce variation into movement through an [[wiki/Optimization Landscape|optimization landscape]].
## See Also
[[wiki/Gradient Descent|Gradient Descent]], [[wiki/Local Optimum|Local Optimum]], [[wiki/Credit Assignment|Credit Assignment]]