 If the theory is meant to describe the reasoning of a decision-maker, the first two interpretations would seem inferior to the third. The problem with the first two interpretations is that the decision-maker might be unaware of some of the logically possible states and outcomes, as well as some of the states and outcomes that the modeller is aware of. (Having said that, one may identify the states and outcomes that the agent is unaware of by reference to those of which the modeller is aware.)