ServiceNow Research

On the Information Complexity of Proper Learners for VC Classes in the Realizable Case


We provide a negative resolution to a conjecture of Steinke and Zakynthinou (2020a), by showing that their bound on the conditional mutual information (CMI) of proper learners of Vapnik–Chervonenkis (VC) classes cannot be improved from d logn + 2 to O(d), where n is the number of i.i.d. training examples. In fact, we exhibit VC classes for which the CMI of any proper learner cannot be bounded by any real-valued function of the VC dimension only.