Lecture 1 Flashcards
Pro’s and cons of AML?
Pro:
Emerging research field
Democratization of ML
Less work
Support Data Scientist, not replace
Con:
General AI
What is AML?
Algorithm selection (combined with hyperparameter optimization)
Hyperparameter optimization
Workflow Synthesis
Neural Architecture Search
Few shot learning
Hyperparameter Optimization
Argmin_(lambda) Loss(Algo_(lambda), TrainSet, ValidSet)
Algorithm Selection
Argmin_(algorithm) Loss(Algo, TrainSet, ValidSet)
CASH
argmin lambda and algorithm
Search Algorithms
Grid
Random
Bayesian Optimization
Bayesian Optimization
Find x with low f(x)
Find promising points with acquisition function (expected improvement)
Repeat for next x
(Not parallelizable)
Expected improvement
z = ( f s t a r − mu) / s i g m a
r e t u r n ( f s t a r − mu) ∗ norm . c d f ( z ) + s i g m a ∗ norm . p d f ( z )
Configuration Spaces
Categorical
Numerical
Conditional Hyperparameters
(Range, Sampling Strat, some shouldnt be optimized(seed))
One armed bandit
Every A, hyperp’s is a bandid
Lever pull is a training run cost (budget)
Successive Halving
Every part of budget, num of A’s that are trained is halved
Budget types
Run time
Observations
Attributes
Suitable hyperparameter value (epoch, ensemble size)
Successive halving: pros
Simple
Parallelizable
Converges to optimum
Strong theoretical foundation
Good results
Successive halving: cons
Extension to random search
Not data efficient
Human designed bandit strat
Learning curves can cross
Good solutions might be dropped