This paper surveys recent dynamic logics of knowledge and belief for a single agent. Many of the recent developments in this area have been driven by analyzing concrete examples. These range from toy examples, such as the infamous muddy children puzzle, to philosophical quandaries, such as Fitch's Paradox , to everyday examples of social interaction . Different logical systems are then judged, in part, on how well they conform to the analyst's intuitions about the relevant set of examples. But this raises an important methodological issue: Implicit assumptions about what the actors know and believe about the situation being modeled often guide the analyst's intuitions. In many cases, it is crucial to make these underlying assumptions explicit. The primary goal of this paper is to demonstrate how this "meta-information " can be made explicit in the formal models of knowledge and belief .