Action Models in Inquisitive Logic Thom van Gessel Abstract: In Dynamic Epistemic Logic, action models are used to encode situations in which agents are uncertain about information being exchanged. These models show how publicly or privately announced statements can bring about change in knowledge. In real communication, questions also play a big part. Asking a question can raise an issue, which typically triggers the recipient to resolve it. Therefore, adding questions and issues to action models makes them more suitable as models of communication. In this thesis, we merge the ideas of Inquisitive Epistemic Logic (IEL) and Action Model Logic (AML) in three different ways. This results in three systems, which can encode the exchange of statements and questions and compute their effects on knowledge and issues. Each of these systems can be regarded as a conservative extension of both AML and IEL, and is provided with a sound and complete axiomatization. Keywords: logic, language