In the group of people with whom I have worked most closely, we recently attempted to dress our visionary goal in words: “to learn enough about human face-to-face interaction that we are able to create an artificial conversational partner that is humanlike”. The “conversational homunculus” figuring in the title of this book represents this “artificial conversational partner”. The vision is motivated by an urge to test computationally our understandings of how human-human interaction functions, and the bulk of my work leads towards the conversational homunculus in one way or another. This book compiles and summarises that work: it sets out with a presenting and providing background and motivation for the long term research goal of creating a humanlike spoken dialogue system, and continues along the lines of an initial iteration of an iterative research process towards that goal, beginning with the planning and collection of human-human interaction corpora, continuing with the analysis and modelling of the human-human corpora, and ending in the implementation of, experimentation with and evaluation of humanlike components for in human-machine interaction. The studies presented have a clear focus on interactive phenomena at the expense of propositional content and syntactic constructs, and typically investigate the regulation of dialogue flow and feedback, or the establishment of mutual understanding and grounding.