Begging the question - proper justification or proper conversation?

Since Aristotle there are two main approaches in the explanation of begging the question (petitio): a dialectical mistake (an improper move in an argumentative dialogue) and an epistemic mistake. According to the latter begging the question is committed when the premises of an argument cannot be known independently of knowing the conclusion of the argument. Dialectical approaches use the notion of a commitment (acceptance, standpoint) and rules of dialogue as their basis. I propose a hybrid model, inspired by Jackson: the rationale for introducing commitments and rules is epistemic.