Question – Answer Games ( extended abstract )

I am in the middle of Manhattan and I am lost. I approach a likely stranger on the road and ask him, pointing to the right: “Is this the way to the railway station?” Discounting for a moment the possibility that I will be ignored and that the stranger will continue on his way (of which the—trivial—game move equivalent would be “I prefer not to answer the question”), I will now get one of three possible answers: “Yes,”, “No,”, and “I don’t know.” Each answer is informative. After the third answer I may ask the same question to someone else. Questions and answers can be analyzed in dynamic epistemic logic, and right questions and right answers in game theory. We focus on dynamic epistemic logic and not on game theory, and our main contribution is a novel link between the two. In this introduction we now first address the question, then the answer, and lastly the game wherein such questions and answers figure. The railway example misses that game aspect, but now consider having to decide between asking the conference chair “Are the outcomes of the submissions already known?” or “Is my submission accepted?” What the best question is to ask, also depends on the answers you may expect or fear.