CMSC 491M/691M - Spring 2003

Discussion Questions for Class #23, April 21

Reading: Levesque, Cohen, and Nunes, "On Acting Together"

• The scenario described on page 95 involves agents who initially are in a state of mutual belief, but lose synchrony when one agent comes to believe something that the other agent is not aware of.
• What would happen if the following assumptions made by Levesque et al. were violated? Are the assumptions reasonable for real-world agent systems?
  • "...each agent has perfect introspection about both his beliefs and goals..."
  • "....beliefs are consistent..."
  • "...goals are consistent with each other and with what is believed."
• What definition does this paper use for commitment to a goal? For intention?
• What's wrong with the first definition of joint commitment (given on page 96)? What's the difference between a weak goal and a joint persistent goal?
• What's the difference between a joint persistent goal and a joint commitment?
• What are the differences and similarities between the SharedPlans framework and Levesque et al.'s model of joint intentions? Do you think either framework is:
  • ...a more accurate model of how people act jointly? Why?
  • ...a better normative model for how agents should act jointly?
  • ...a more useful model for building practical systems?
• Levesque et al. are particularly interested in linguistic interactions in the context of joint activity, "seen as attempts to establish and maintain... mutual beliefs." In the joint commitment framework, what clues might an agent have that it needed to communicate with another agent? How would the shared knowledge of joint commitments make their communication more efficient?