CMSC 477/677 - Spring 2007
Discussion Questions for Class #16, March 29
Reading: Levesque, Cohen, and Nunes, "On Acting Together";
Grosz, Hunsberger, and Kraus, "Planning and Acting Together."
Levesque, Cohen, and Nunes
- 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. (near the end of page 95) 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?
- 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?
Grosz, Hunsberger, and Kraus
- Grosz et al. give three key aspects of SharedPlans that make them
useful for collaborative agents. Why are each of these aspects
important? Give an example of situations where lacking each of these
aspects would cause collaborative failures or inefficiencies.
- "provision for agents to interleave planning and acting"
- "inclusion of commitments that can lead agents to behave
helpfully"
- "constraints that prohibit adoption of conflicting intentions"
- What is the difference between intention to and
intention that in the SharedPlans framework? Why are both of
these forms of intention necessary for collaborative planning?
- 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?