A control system for a modular, mixed initiative, human-machine interface. The control system comprises moves, the moves defining units of interaction about a topic of information. The moves comprise at least one system move and at least one user move. Each system move is structured such that it contains information regarding pre-processing to be performed, information to develop a prompt to be issued to the user and information that enables possible user moves which can follow the system move to be listed. Each user move is structured such that it contains information relating to interpretation grammars that trigger the user move, information relating to processing to be performed based upon received and recognized data and information regarding the next move to be invoked. A corresponding method is provided.