Abstract: Vapnik's "Fundamental theorem of statistical learning" states that for binary classification prediction
the following conditions of a class H of predictors are equivalent:
1) H is PAC learnable (in both the realizable and the agnostic cases)
2) H has the uniform convergence property (hence learnable by any ERM learner).
3) H has a finite VC dimension
However, for other natural learning scenarios this equivalence breaks down.
This has been shown for a general model of learning by Shalev-Shwartz et al
for a model of learning from unlabeled samples when the labeling rule is known by Ben-David et al
In this tutorial I will survey those results, where learnability holds in spite of the failure of uniform convergence.
I shall discuss what is known about the existence of a dimension that characterizes learnability in such cases.
In particular, I will present a recent result that uses set theory tools to prove that there can be no
combinatorial dimension that characterizes learnability in Vapnik's General Model of Statistical Learning