Page 202 - Socially Intelligent Agents Creating Relationships with Computers and Robots

Socially Situated Planning 185

change my plans. [Looks concerned, scratches head, then devises a possible joint plan.] Ihave
a suggestion. Could you drive the car to the-quicky-mart with-me then I could drive the car to
the beach. [Note that neither agent has been given the goal of returning home.]
Jack: [Adds Steve’s suggested joint plan, determines that it is consistent with his own, and
agrees to form a joint commitment to the shared plan.] Sounds good to me.
3. Social Control Programs

A small change in an agent’s static social state can result in a dramatic
change in behavior because reasoning at the social level is highly leveraged.
Social reasoning is conditioned on dynamic social features that encapsulate
a good deal of domain-independent inference and social control primitives al-
low for considerable differences in how plans are generated and executed at the
base level. Social reasoning is represented as a set of condition actions rules
that operate at this meta-layer. Social state components serve as the conditions
for these social rules whereas control primitives define the space of possible
actions.

3.1 Social State
An agent’s social state is composed of dynamic and static components. Dy-
namic components are further divided into communicative state, plan state, and
emotional state.
Communicative State: The communicative state tracks what information has
been communicated to different agents and maintains any communicative obli-
gations that arise from speech acts. When Steve communicates a plan to Jack,
Steve’s social layer records that Jack knows this plan, and persists in knowing
it until Steve’s planning layer modifies it, at which point Steve’s social layer
records that Jack’s knowledge is out of date. If Jack requests Steve’s current
plans, the social layer creates communicative obligations: the fact that Steve
owes Jack a response is recorded in each agent’s social layer (though whether
Steve satisfies this obligation is up to Steve’s social control program).
Plan State: At the base-level planning layer, all activities that an agent is aware
of (whether they come from its own planning or are communicated from out-
side) are stored in a single plan network, allowing the planner to reason about
the interrelationship between these activities. The social layer keeps track of
the fact that different subsets of this plan network correspond to different plans
– some belonging to the agent and some corresponding to (what the agent be-
lieves to be) plans of other agents. The social layer also computes a variety of
high-level relations between plans. Plans can contain threats and the plans of
one agent can introduce threats or be threatened by the plans of another agent
(such relations are computed using the basic plan-evaluation routines provided
by standard planning systems). Plans of one agent can also be relevant to other