Ignorance and its formal limits

Over the last decades, several works in epistemic logic focused on the challenge of modeling ignorance. Given that this notion is considered as intricate and multi-layered, one of the difficulties in this endeavor lies in the lack of consensus regarding the specific form of ignorance being targeted for modeling. The aim of this article is to provide an overview of diverse frameworks for representing ignorance, delineate the particular forms of ignorance captured by each framework, and propose formal definitions for certain types of ignorance that lack explicit treatment in the existing literature.