Parikh will discuss three issues regarding group knowledge:

1. How can we tell by the behavior of agents in a group what their beliefs are or at least what they are not?For instance someone going out without an umbrella reveals the fact that she does not know (believe) it is raining.She does not need to /tell/ us, we can infer what she believes from what she /does/.(This is a weak notion of belief applicable also to children and animals.) We deal not only with beliefs of agents about the world but also with their beliefs about the beliefs of other agents and so on.
2. How can we influence the behavior of agents by influencing what they know or what they believe? Parikh will give a theoretical account of this and also show that for any state of knowledge described by a finite Kripke structure, there is an n-tuple of signals that can be sent, one to each agent which will create precisely that state of knowledge.
3. Parikh will define two kinds of agents, /cautious/ and /aggressive/ and show how they may act differently in the same situation with the same knowledge and the same preferences. When we seek to influence the behavior of agents, it sometimes helps to know if they are cautious or aggressive.

The work in 1) is work under progress. Work in 2) and 3) is joint with Cagil Tasdemir, a doctoral student at CUNY, and Andreas Witzel, now working at Google in New York.