Information Theoretical Analysis of Unfair Rating Attacks under Subjectivity

Ratings provided by advisors can help an advisee to make decisions, e.g., which seller to select in e-commerce. Unfair rating attacks – where dishonest ratings are provided to mislead the advisee – impact the accuracy of decision making. Current literature focuses on specific classes of unfair rating attacks, but this does not provide a complete picture of the attacks. We provide the first formal study that addresses all attack behaviour that is possible within a given system. We propose a probabilistic modelling of rating behaviour, and apply information theory to quantitatively measure the impact of attacks. In particular, we can identify the attack with the worst impact. In the simple case, honest advisors report the truth straightforwardly, and attackers rate strategically. In real systems, the truth (or an advisor’s view on it) may be subjective, making even honest ratings inaccurate. Although there exist methods to deal with subjective ratings, whether subjectivity influences the effect of unfair rating attacks was an open question. We discover that subjectivity decreases the robustness against attacks

The role of Criticism in the Dynamics of Performance Evaluation Systems

Drawing on the concept of « trial », developed by French sociologists, this article analyzes the dynamics of employees’ performance evaluation systems, particularly those involving accounting performance measures. A case study is presented as an illustration of our proposal to consider these systems as one of the major trials in the business world, that is, social arrangements organizing the testing of people and resulting in ordering them, and further in consistent social goods allocation. This analysis emphasizes the role of criticism in the dynamics and evolution of performance evaluation systems and enables us to revisit concepts like controllability or objectivity which have been presented for decades as cornerstones of performance evaluation systems either in management control or in human resource management fields.Criticism; performance evaluation systems; fairness; objectivity; controllability; legitimacy; bonus

Checking the fact-checkers in 2008: predicting political ad scrutiny and assessing consistency

Which types of political ads are most likely to draw criticism from fact-checkers? Are fact-checkers consistent in their evaluations of political ads? Examining general election television ads from the 2008 U.S. presidential race, and based upon the evaluations of FactCheck.org, PolitiFact.com, and the Washington Post's Fact Checker, this study demonstrates it was the attack ads from candidates that were most likely to draw scrutiny from the fact-checkers. Most importantly, a high level of agreement between the fact-checkers indicates their success at selecting political claims that can be consistently evaluated. While political advertisers are increasingly using evidence to support their claims, what may be more critical in drawing evaluations from fact-checkers is the verifiability of a claim. The implications of consistent fact-checking on the public, political actors, journalism and democracy are discussed. With the revelation that fact-checking can be consistently practiced, localized efforts at fact-checking need encouragement, particularly as political TV ads increasingly drown out other potential sources of information for the public and increasingly are used in downballot races, local initiatives, referendums and judicial races

Measuring Institutions: Indicators of Political and Economic Institutions in Namibia: 1884 - 2008

This paper presents a database on institutional measures for Namibia for the period 1884 to 2008. Using the techniques of principal components and factor analysis in aggregating these indicators, the study does two things. First, it illustrates a methodology for constructing de jure and de facto institutional measures by means of using pieces of legislation and quantitative data, respectively. Secondly, these indicators are used to assess the nature of political and economic institutional transformation from the colonial legacy to the modern outcome using Namibia as a natural experiment. The new indicators while covering a long time period (1884-2008), correlate fairly well with some of the widely used institutional indices produced by the Freedom House and the Heritage foundation.Namibia Institutional Indicators Political Freedom Property Rights Judicial Independence Political Instability

Performance Based Pay: Is it a Functional Alternative in Government?

The use of performance-based, or incentive based, compensation plans is ubiquitous in the private sector. Private business operates under the belief that the use of incentives leads to increased performance from employees and higher profits for the companies. This study is centered on the function of those performance-based pay plans within the government. Its purpose is to determine if the use of such pay plans is effective, both for the efficiency of government organizations and the motivation of employees. Through the analysis of government documents and organizational plans, and interviews of human resource managers and employees, this study analyzes performance-based pay and its effectiveness in the public sector

Provably robust decisions based on potentially malicious sources of information

Ministry of Education, Singapore under its Academic Research Funding Tier

Promoting Honesty in Electronic Marketplaces: Combining Trust Modeling and Incentive Mechanism Design

This thesis work is in the area of modeling trust in multi-agent systems, systems of software agents designed to act on behalf of users (buyers and sellers), in applications such as e-commerce. The focus is on developing an approach for buyers to model the trustworthiness of sellers in order to make effective decisions about which sellers to select for business. One challenge is the problem of unfair ratings, which arises when modeling the trust of sellers relies on ratings provided by other buyers (called advisors). Existing approaches for coping with this problem fail in scenarios where the majority of advisors are dishonest, buyers do not have much personal experience with sellers, advisors try to flood the trust modeling system with unfair ratings, and sellers vary their behavior widely. We propose a novel personalized approach for effectively modeling trustworthiness of advisors, allowing a buyer to 1) model the private reputation of an advisor based on their ratings for commonly rated sellers 2) model the public reputation of the advisor based on all ratings for the sellers ever rated by that agent 3) flexibly weight the private and public reputation into one combined measure of the trustworthiness of the advisor. Our approach tracks ratings provided according to their time windows and limits the ratings accepted, in order to cope with advisors flooding the system and to deal with changes in agents' behavior. Experimental evidence demonstrates that our model outperforms other models in detecting dishonest advisors and is able to assist buyers to gain the largest profit when doing business with sellers. Equipped with this richer method for modeling trustworthiness of advisors, we then embed this reasoning into a novel trust-based incentive mechanism to encourage agents to be honest. In this mechanism, buyers select the most trustworthy advisors as their neighbors from which they can ask advice about sellers, forming a social network. In contrast with other researchers, we also have sellers model the reputation of buyers. Sellers will offer better rewards to satisfy buyers that are well respected in the social network, in order to build their own reputation. We provide precise formulae used by sellers when reasoning about immediate and future profit to determine their bidding behavior and the rewards to buyers, and emphasize the importance for buyers to adopt a strategy to limit the number of sellers that are considered for each good to be purchased. We theoretically prove that our mechanism promotes honesty from buyers in reporting seller ratings, and honesty from sellers in delivering products as promised. We also provide a series of experimental results in a simulated dynamic environment where agents may be arriving and departing. This provides a stronger defense of the mechanism as one that is robust to important conditions in the marketplace. Our experiments clearly show the gains in profit enjoyed by both honest sellers and honest buyers when our mechanism is introduced and our proposed strategies are followed. In general, our research will serve to promote honesty amongst buyers and sellers in e-marketplaces. Our particular proposal of allowing sellers to model buyers opens a new direction in trust modeling research. The novel direction of designing an incentive mechanism based on trust modeling and using this mechanism to further help trust modeling by diminishing the problem of unfair ratings will hope to bridge researchers in the areas of trust modeling and mechanism design

Anti-Equivalence: Pragmatics of post-liberal dispute

In the early 21st century, liberal democracies have witnessed their foundational norms of critique and deliberation being disrupted by a combination of populist and technological forces. A distinctive style of dispute has appeared, in which a speaker denounces the unfairness of all liberal and institutional systems of equivalence, including the measures of law, economics and the various other ‘tests’ which convention scholars have deemed core to organisations. The article reviews how sociologists of critique have tended to treat critical capacities as oriented towards consensus, but then considers how technologies of real-time ‘control’ circumvent liberal critique altogether. In response, a different type of dispute emerges in the digital public sphere, which abandons equivalences in general, instead adopting a non-representational template of warfare. This style of post-liberal dispute is manifest in the rhetoric of populists, but does not originate there