Research Interests

Robin Cohen conducts research in the artificial intelligence subfields of multiagent systems, user modeling and intelligent interaction. Most recently the focus of her research has been on modeling trust in multiagent systems, with connections to social networking and to applications of electronic commerce. She has also been exploring trust modeling for the application of transportation (in mobile vehicular ad-hoc networks) and in the context of peer-based intelligent tutoring systems.

With Jie Zhang, she explored scenarios where buying agents make use of advice provided by other buying agents in order to select the most appropriate selling agents. Included in this research is an approach that allows the combination of private and public modeling of the advisor's trustworthiness. The approach introduces as well incentives for honest reporting from advisors, through rewards provided by sellers to those advisors accepted into a large number of social networks of other buying agents.

With Reid Kerr, Professor Cohen has investigated the promotion of secure electronic marketplaces. This research first explored some of the common vulnerabilities in existing trust and reputation models, leading to a demonstration of how smart cheating agents can prosper even when their trustworthiness is being modeled. This in turn resulted in the design of a valuable testbed for measuring the performance of any trust and reputation modeling system. From here, work with Kerr focused on the critical challenge of collusion in multiagent systems, including techniques aimed at recognizing clusters of agents that avoid harm and instead produce benefit to each other.

In dynamic environments with sparse connections, it is beneficial to employ a multi-dimensional trust model, which takes into consideration the role of each agent that provides information, as well as its location, the time of the communication, its known trustworthiness from direct experience and its trustworthiness reflected from majority opinion in the multiagent system. This approach was explored for the application of mobile vehicular ad-hoc networks, for which we developed as well an extensive simulation framework for trust-based travel decision making.

In environments where student learning can be achieved on the basis of the previous experience of peers, the challenge is to determine the appropriate social network to employ -- which peers are most reputable and which learning experiences have been most beneficial, for students bearing some similarity to the current student. This is the topic of research conducted with John Champaign, which also integrated a novel approach for reasoning about which commentary on learning objects to present to users, based on a modeling of reputation and similiarity.

With Noel Sardana, research has investigated how to use trust in order to streamline the presentation of messages in social networking environments. An initial model integrated the concept of credibility, to balance consideration of similarity, to cope with folklore. From here, the research explored a principled Bayesian approach in order to learn from observations, against the backdrop of user utilities. This enables an examination of the use of trust modeling, for decision making.

Most recently, Professor Cohen has been developing an approach  to engender trust in multiagent systems, working with Thomas Tran. This enables a more complete viewpoint of the dynamics of trust modeling, examined from the perspective of the agent who is being modeled.

Other research has focused on the topic of multiagent resource allocation with preemption, conducted with John Doucette and Graham Pinhey, for cooperative environments. The challenge is to enable effective coordination of agents, even with dynamic task arrivals, through a modeling and exchange of plans and their utilities.

A longstanding instructor of the social implications of computing, Professor Cohen has also recently been examining how to develop technological solutions to social problems of computers, including offering a graduate level course in this topic area.

Degrees and Awards

BA (McGill), MSc, PhD (Toronto)

  • Senior Member, AAAI (2014)
  • Associate Dean Research, Faculty of Mathematics (2011-2013)
  • David R. Cheriton Faculty Fellow, University of Waterloo (2010-2013)
  • Best Paper Award, International Conference on Information Technology and Convergence (ITCS) with C.Cheng, J. Zhang and P.Ho (2010)
  • Award for Excellence in Graduate Supervision, University of Waterloo (2009)
  • Faculty of Mathematics Distinguished Teaching Award, University of Waterloo (2008)
  • Best Paper Award Canadian Semantic Web Symposium with J. Zhang (2006)
  • Best Paper Award Conference on Privacy, Security and Trust (PST) with K. Regan and P. Poupart (2005)
  • Faculty of Mathematics Faculty Fellowship, University of Waterloo (2002-2005)

Industrial and Sabbatical Experience

Professor Cohen’s most recent connection to industry has arisen as result of an NSERC Strategic Research Network project known as hSITE, aimed at developing technological enhancements to improve the delivery of healthcare in both hospital and homecare settings (with lead PI David Plant (Electrical Engineering, McGill University)). She has collaborated primarily with a team of researchers at the University of Toronto (including from industrial engineering and from nursing), who in turn have connections to industrial partners, interested in exploring sensing and networking solutions for healthcare. Professor Cohen's involvement in this project is primarily focused on reasoning about interaction with medical experts for hospital decision making.

Representative Publications

J. Champaign, R. Cohen, N. Sardana and J. Doucette; A framework to restrict the viewing of peer commentary on web objects based on trust modeling; Social Network Analysis and Mining; 25 pages; to appear, 2014.

R. Kerr and R. Cohen; Detecting and Identifying Coalitions; Proceedings of AAMAS 2012; 2012.

J. Zhang and R. Cohen. Design of a mechanism for promoting honesty in e-marketplaces; Proceedings of AAAI 2007; 2007.

J. Finnson, J. Zhang, T. Tran, U. Minhas and R. Cohen; A framework for modeling trustworthiness of users in mobile vehicular ad-hoc networks and its validation through simulated traffic flow; Proceedings of UMAP 2012; 2012.

T. Tran, R. Cohen and E. Langlois; Establishing trust in multiagent environments: realizing the comprehensive trust management dream; Proceedings of TRUST 2014 workshop at AAMAS 2014; 2014.

G. Pinhey, J. Doucette and R. Cohen. Distributed multiagent resource allocation with adaptive preemption for dynamic tasks. Proceedings of AAMAS 2014; 2014.

University of Waterloo
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