1950s-80s
Symbolic AI era
expert systems, logic programming
1990s-2000s
Classical ML
SVMs, decision trees, hand-engineered features
2012
Deep learning breakout
AlexNet on ImageNet, GPU training
2017-now
Scale era
Transformers + massive data + compute
Formally, machine learning is the search for a function , parameterized by , that minimizes expected loss over the true (unknown) data distribution :