[Apologies for multiple postings]

Please notice the unusual talk time: Thursday (11/18) at 11 am.

*    GRAND Seminar


Trust and Reputation in Multiagent Systems: Strategies and Dynamics


Nov/18/2010, Thursday 11am-noon. ENGR 4201


Christopher Hazard
Post-Doctoral Researcher
North Carolina State University


Prof. Sean Luke


In multiagent interactions, such as e-commerce and peer-to-peer file
sharing, being able to accurately assess the trustworthiness of other
agents is important for agents to protect themselves from losing
utility. We focus on an agents' discount factors (time preference of
utility) as a direct measure of the agent's trustworthiness in a
number of settings. We prove that an agent's discount factor, when in
context of the agent's valuations and capabilities, is isomorphic to
trustworthiness for a set of reasonably general assumptions and
definitions. Further, we propose a general list of desiderata for
trust systems and discuss how discount factors as trustworthiness meet
these desiderata and discuss how discount factors are a robust measure
when entering commitments with adverse selection and moral hazards.

Despite the large body of work in reputation and trust in dynamic
multiagent environments, no metrics exist to directly and
quantitatively evaluate and compare reputation systems. We present a
common conceptual interface for reputation systems and a set of four
measurable desiderata that are broadly applicable across multiple
domains, inspired by dynamical systems theory. We discuss the
implications, strengths, and limitations of our desiderata. Our
discount factor as trustworthiness model performs well across the
desiderata when measured against other established reputation models
from the literature in a reciprocity setting.


Christopher Hazard is a Post-Doctoral Researcher at North Carolina
State University, with interests in emergent behavior, strategic
behavior, and scalability in multiagent systems systems.  Dr. Hazard
has also worked at Motorola and Kiva Systems.  He is also the founder
of the game studio Hazardous Software, and the producer of Achron, a
real-time strategy game which permits time travel.

*Jyh-Ming Lien*
Assistant Professor, George Mason University