Congrats: a Configurable Granular Trust Scheme for Effective Seller Selection in an E-marketplace

Problem. The e-marketplace of today, with millions of buyers and sellers who never get to meet face to face, is susceptible to the presence of dishonest and fraudulent participants, prowling on unsuspecting trading partners to cheat in transactions, thereby increasing their profit to the detriment of their victims. There is also the multiplicity of goods and services with varying prices and quality, offered by a mix of honest and dishonest vendors. In order to participate in trade without incurring substantial loss, participants rely on intelligent agents using a trust evaluation scheme for partner selection. Making good deals thus depends on the ability of the intelligent agents to evaluate trading partners and picking only trustworthy ones. However, the existing trust evaluation schemes do not adequately protect buyers in the e-marketplace; hence, this study focused on designing a new trust evaluation scheme for buyer agents to use to effectively select sellers. -- Method. To increase the overall performance of intelligent agents and to limit loss for buyers in an e-marketplace, I propose CONGRATS—a configurable granular trust estimation scheme for effective seller selection. The proposed model used historical feedback ratings from multiple sources to estimate trust along multiple dimensions. I simulated a mini e-marketplace to generate the data needed for performance evaluation of the proposed model alongside two existing trust estimation schemes—FIRE and MDT. -- Results. At the peak of performance of CONGRATS, T1 sellers with the highest trust level accounted for about 45% of the total sales as against less than 10% recorded by the least trustworthy (T5) sellers. Compared to FIRE and MDT, CONGRATS had a performance gain of 15% and 30%, respectively, as well as an average earning of 0.89 (out of 1.0) per transaction in contrast to 0.70 and 0.62 per transaction respectively. Cumulative utility gain among buyer groups stood at 612.35 as contrasted to 518.96 and 421.28 for the FIRE and MDT models respectively. -- Conclusions. Modeling trust along multiple dimensions and gathering trust information from many different sources can significantly enhance the trust estimation scheme used by intelligent agents in an e-marketplace. This means that more transactions will occur between buyers and sellers that are more trustworthy. Inarguably, this will reduce loss to an infinitesimal level and consequently boost buyer confidenc

A Learning Automata Based Solution to Service Selection in Stochastic Environments

With the abundance of services available in today’s world, identifying those of high quality is becoming increasingly difficult. Reputation systems can offer generic recommendations by aggregating user provided opinions about service quality, however, are prone to ballot stuffing and badmouthing . In general, unfair ratings may degrade the trustworthiness of reputation systems, and changes in service quality over time render previous ratings unreliable. In this paper, we provide a novel solution to the above problems based on Learning Automata (LA), which can learn the optimal action when operating in unknown stochastic environments. Furthermore, they combine rapid and accurate convergence with low computational complexity. In additional to its computational simplicity, unlike most reported approaches, our scheme does not require prior knowledge of the degree of any of the above mentioned problems with reputation systems. Instead, it gradually learns which users provide fair ratings, and which users provide unfair ratings, even when users unintentionally make mistakes. Comprehensive empirical results show that our LA based scheme efficiently handles any degree of unfair ratings (as long as ratings are binary). Furthermore, if the quality of services and/or the trustworthiness of users change, our scheme is able to robustly track such changes over time. Finally, the scheme is ideal for decentralized processing. Accordingly, we believe that our LA based scheme forms a promising basis for improving the performance of reputation systems in general

A survey of security issue in multi-agent systems

Multi-agent systems have attracted the attention of researchers because of agents' automatic, pro-active, and dynamic problem solving behaviors. Consequently, there has been a rapid development in agent technology which has enabled us to provide or receive useful and convenient services in a variety of areas such as banking, transportation, e-business, and healthcare. In many of these services, it is, however, necessary that security is guaranteed. Unless we guarantee the security services based on agent-based systems, these services will face significant deployment problems. In this paper, we survey existing work related to security in multi-agent systems, especially focused on access control and trust/reputation, and then present our analyses. We also present existing problems and discuss future research challenges. © Springer Science+Business Media B.V 2011

The SECURE collaboration model

The SECURE project has shown how trust can be made computationally tractable while retaining a reasonable connection with human and social notions of trust. SECURE has produced a well-founded theory of trust that has been tested and refined through use in real software such as collaborative spam filtering and electronic purse. The software comprises the SECURE kernel with extensions for policy specification by application developers. It has yet to be applied to large-scale, multi-domain distributed systems taking different application contexts into account. The project has not considered privacy in evidence distribution, a crucial issue for many application domains, including public services such as healthcare and police. The SECURE collaboration model has similarities with the trust domain concept, embodying the interaction set of a principal, but SECURE is primarily concerned with pseudonymous entities rather than domain-structured systems

Understanding the Jury with the Help of Social Science

A Review of Inside the Jury by Reid Hastie, Steven Penrod and Nancy Penningto

Quality of Information in Mobile Crowdsensing: Survey and Research Challenges

Smartphones have become the most pervasive devices in people's lives, and are clearly transforming the way we live and perceive technology. Today's smartphones benefit from almost ubiquitous Internet connectivity and come equipped with a plethora of inexpensive yet powerful embedded sensors, such as accelerometer, gyroscope, microphone, and camera. This unique combination has enabled revolutionary applications based on the mobile crowdsensing paradigm, such as real-time road traffic monitoring, air and noise pollution, crime control, and wildlife monitoring, just to name a few. Differently from prior sensing paradigms, humans are now the primary actors of the sensing process, since they become fundamental in retrieving reliable and up-to-date information about the event being monitored. As humans may behave unreliably or maliciously, assessing and guaranteeing Quality of Information (QoI) becomes more important than ever. In this paper, we provide a new framework for defining and enforcing the QoI in mobile crowdsensing, and analyze in depth the current state-of-the-art on the topic. We also outline novel research challenges, along with possible directions of future work.Comment: To appear in ACM Transactions on Sensor Networks (TOSN

The editorial meeting discussion as an argumentative activity type

A still uninvestigated argumentative reasoning hides behind news texts, in the discussions surrounding the writing process. I try to fill this gap by reconstructing how newsroom decision-making functions from a combined argumentative and discourse analytical perspective. In order to do so, I analyze the editorial meeting discussion about a potential news item and its production as an argumentative activity type, using a French- and German-language corpus collected at the Swiss public broadcast service