Tutorial: Implicit Bias II
summary
Experiments fit MNIST nets with 8,16,64,512,1000+ hidden units and show zero training error on random labels (Zhang et al.), yet test error keeps falling; kernel SVM and 1‑NN give analogous behavior. Optimization, not the class size, creates the bias: gradient descent converges to a minimum L2‑norm/max‑margin direction while coordinate descent yields an L1‑style bias. Matrix‑completion (U×V) trained by GD attains low test error (≈10% → ≈5% with different GD variants). Infinite‑width ReLU limits minimize ∫|f''| and benign overfitting arises under specific covariance spectral conditions.
AI-written summary · about
chapters (34)
- 0:00Introduction and experiment
- 1:06Classic theory vs practice
- 2:51The generalization mystery
- 5:07Shattering and generalization
- 7:20Implicit bias in algorithms
- 9:35Complexity and simplicity
- 12:15Finding generalizable minima
- 14:17Complexity measures
- 17:18Least squares bias
- 19:42Optimization and simplicity
- 22:55Logistic loss divergence
- 25:04Algorithm-induced bias
- 26:52Regularization and time
- 29:15Infinite network concept
- 33:45Matrix completion example
- 38:10Numerical stability
- 42:25Linear networks
- 46:11ReLU networks
- 49:22Architecture and geometry
- 52:01Complexity approach
- 55:28Approximation limitations
- 57:36Matrix factorization rank
- 1:02:14Theory vs phenomena
- 1:04:26Overfitting definition
- 1:06:54Double descent
- 1:10:16Benign overfitting
- 1:13:54Characterizing overfitting
- 1:15:35Uniform convergence limits
- 1:18:09Linear regression conditions
- 1:20:39Pareto frontier
- 1:23:14Summary and future work
- 1:25:33Uniform convergence debate
- 1:27:49Mathematics vs engineering
- 1:29:18Questions and answers
related talks
46mOn the Foundations of Deep Learning: SGD, Overparametrization, and Generalization
01h 17mImplicit Regularization I
50mFrom Classical Statistics to Modern Machine Learning
01h 01mOptimization's Untold Gift to Learning: Implicit Regularization
01h 14mRecent Developments in Over-parametrized Neural Networks, Part I
50mLearning and Generalization in Over-parametrized Neural Networks, Going Beyond Kernels
01h 23mImplicit Regularization II
44mMachine Learning Exposed
