 Our main focus in this entry is a second approach to dynamic semantics, although we will compare things to DRT along the way. In this second approach, dynamic meanings are types of actions, things that are individuated by the changes they effect. This is the approach associated with dynamic predicate logic (DPL, Groenendijk and Stokhof 1991a). According to this dynamic semantic tradition, a meaning is a specification of how a receiver’s information state would be modified. It could for instance be a function that maps an old information state to one which has been updated with the information that the meaning embodies. Alternatively, it could be a relation that expresses the kind of information change that the meaning brings about. (For early work in this tradition, see Groenendijk and Stokhof 1991a,b; Muskens 1991; Dekker 1993; Vermeulen 1993; van Eijck 1994; Vermeulen 1994; Krahmer 1995; van den Berg 1996; Groenendijk et al. 1996; Aloni 1997; Muskens et al. 1997).