Stereotype reputation with limited observability

Assessing trust and reputation is essential in multi-agent systems where agents must decide who to interact with. Assessment typically relies on the direct experience of a trustor with a trustee agent, or on information from witnesses. Where direct or witness information is unavailable, such as when agent turnover is high, stereotypes learned from common traits and behaviour can provide this information. Such traits may be only partially or subjectively observed, with witnesses not observing traits of some trustees or interpreting their observations differently. Existing stereotype-based techniques are unable to account for such partial observability and subjectivity. In this paper we propose a method for extracting information from witness observations that enables stereotypes to be applied in partially and subjectively observable dynamic environments. Specifically, we present a mechanism for learning translations between observations made by trustor and witness agents with subjective interpretations of traits. We show through simulations that such translation is necessary for reliable reputation assessments in dynamic environments with partial and subjective observability

Stereotype reputation with limited observability

Assessing trust and reputation is essential in multi-agent systems where agents must decide who to interact with. Assessment typically relies on the direct experience of a trustor with a trustee agent, or on information from witnesses. Where direct or witness information is unavailable, such as when agent turnover is high, stereotypes learned from common traits and behaviour can provide this information. Such traits may be only partially or subjectively observed, with witnesses not observing traits of some trustees or interpreting their observations differently. Existing stereotype-based techniques are unable to account for such partial observability and subjectivity. In this paper we propose a method for extracting information from witness observations that enables stereotypes to be applied in partially and subjectively observable dynamic environments. Specifically, we present a mechanism for learning translations between observations made by trustor and witness agents with subjective interpretations of traits. We show through simulations that such translation is necessary for reliable reputation assessments in dynamic environments with partial and subjective observability

Dynamic Credibility Threshold Assignment in Trust and Reputation Mechanisms Using PID Controller

In online shopping buyers do not have enough information about sellers and cannot inspect the products before purchasing them. To help buyers find reliable sellers, online marketplaces deploy Trust and Reputation Management (TRM) systems. These systems aggregate buyers’ feedback about the sellers they have interacted with and about the products they have purchased, to inform users within the marketplace about the sellers and products before making purchases. Thus positive customer feedback has become a valuable asset for each seller in order to attract more business. This naturally creates incentives for cheating, in terms of introducing fake positive feedback. Therefore, an important responsibility of TRM systems is to aid buyers find genuine feedback (reviews) about different sellers. Recent TRM systems achieve this goal by selecting and assigning credible advisers to any new customer/buyer. These advisers are selected among the buyers who have had experience with a number of sellers and have provided feedback for their services and goods. As people differ in their tastes, the buyer feedback that would be most useful should come from advisers with similar tastes and values. In addition, the advisers should be honest, i.e. provide truthful reviews and ratings, and not malicious, i.e. not collude with sellers to favour them or with other buyers to badmouth some sellers. Defining the boundary between dishonest and honest advisers is very important. However, currently, there is no systematic approach for setting the honesty threshold which divides benevolent advisers from the malicious ones. The thesis addresses this problem and proposes a market-adaptive honesty threshold management mechanism. In this mechanism the TRM system forms a feedback system which monitors the current status of the e-marketplace. According to the status of the e-marketplace the feedback system improves the performance utilizing PID controller from the field of control systems. The responsibility of this controller is to set the the suitable value of honesty threshold. The results of experiments, using simulation and real-world dataset show that the market-adaptive honesty threshold allows to optimize the performance of the marketplace with respect to throughput and buyer satisfaction

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

Incivility in Pre-Registration Nursing Education: a Phenomenological Exploration of the Experiences of Student Nurses, Nurse Tutors and Nurse Mentors in a UK Higher Education Institution

This study provides a unique insight into incivility in pre-registration nursing education through a phenomenological exploration of the experiences of student nurses, nurse tutors and nurse mentors. Incivility is the display of intimidating, rude, disruptive or undesirable behaviours which, in the context of nursing education and practice, has the potential to impact negatively on student learning and patient outcomes. However, despite the potential consequences and the fact that it is a globally recognised phenomenon, very little is known about incivility in nursing education in the United Kingdom. A phenomenological qualitative design was used to explore the experiences of students, mentors and nurse tutors who were assessing, teaching or studying, on a three-year degree level pre-registration nursing programme. Data was collected by conducting twenty-five in-depth, semi-structured, face-to-face interviews which were audio-recorded and transcribed verbatim and the framework for analysis was informed by the work of J. A. Smith, Flowers, & Larkin (2009) and Miles, Huberman, & Saldana (2014). Overall, four major themes emerged (Distraction; Power; Impact on Learning; and Invisibility) along with five minor themes (Emotional Impact, Knowing and Not-knowing; Verbal and Non-verbal Incivilities; Lack of Interest; and Lack of Respect). There were also minor themes specific to the individual participant groups such as Being Nameless (students) and Lateness (mentors). The findings demonstrate the links between incivility, learning and emotion, and bring to the fore previously unseen dimensions such as Invisibility and Knowing and Not-knowing. They also identify a wide range of potential contributory factors. Of particular importance is the explication of learning impact as this aspect has hitherto been little explored and yet is of great significance to student learning outcomes and therefore ultimately, to patient care. Consequently, the recommendations have policy and resource implications for the providers of nurse education. The research was conducted in a higher education institution in the south east of England where the researcher, a registered nurse teacher, works in an academic leadership role. It appears to be the first phenomenological exploration of incivility in the context of nursing education in the UK, and as such it provides a rich and contextualised exploration that others working in similar settings can learn from. It also adds a UK perspective to a phenomenon that is reported by nurse educators around the world, and so makes an original knowledge contribution to the global nursing community

Trust and reputation management in decentralized systems

In large, open and distributed systems, agents are often used to represent users and act on their behalves. Agents can provide good or bad services or act honestly or dishonestly. Trust and reputation mechanisms are used to distinguish good services from bad ones or honest agents from dishonest ones. My research is focused on trust and reputation management in decentralized systems. Compared with centralized systems, decentralized systems are more difficult and inefficient for agents to find and collect information to build trust and reputation. In this thesis, I propose a Bayesian network-based trust model. It provides a flexible way to present differentiated trust and combine different aspects of trust that can meet agents’ different needs. As a complementary element, I propose a super-agent based approach that facilitates reputation management in decentralized networks. The idea of allowing super-agents to form interest-based communities further enables flexible reputation management among groups of agents. A reward mechanism creates incentives for super-agents to contribute their resources and to be honest. As a single package, my work is able to promote effective, efficient and flexible trust and reputation management in decentralized systems

The role of peer-facilitated reflection in critical incident analysis amongst physical therapist assistant students

This research examines the role that peer-facilitated reflection (PFR) plays in influencing the abilities of physical therapist assistant (PTA) students to cope with critical incidents in their academic and clinical coursework. Physical therapist assistants are expected to possess well-developed critical thinking abilities upon graduation that will guide them through professional practice. Several scholars contend that critical thinking abilities should be developed within the curriculum, and that they are best cultivated through reflective practice. However, traditional modes of curricular-based reflective practice have come under scrutiny, revealing shortcomings in their efficacy. These include: a theory-practice gap, ineffective facilitation, and deficient models of assessment. Consequently, a model of PFR was proposed as a more utile reflective approach to develop critical thinking amongst PTA students. An interpretivist investigation was carried out through an action research methodology using Flanagan’s critical incident technique, which favors reflection and planning based upon a significant event. Peer-reflective discussions were implemented into the curriculum of a PTA program. Student participants collectively reflected and developed action plans to put into practice. Data gleaned from post-discussion interviews and questionnaires was examined in light of the criticisms levied against reflective practice and was used to determine the effectiveness of the PFR approach. Findings indicated that students viewed PFR positively, and that they felt the discussion helped them cope with challenges confronted in their academic program. Observational analysis revealed challenges with facilitating reflective discussions, such as having faculty present and keeping discussions focused. Ameliorating steps were implemented for subsequent The Role of Peer-Facilitated Reflection iv discussions that removed faculty from the reflective process and that trained students to effectively lead their own discussions. An assessment model was adapted for this study that examined outcomes based upon the students’ own assessments. Though still in its development, it offers promise as a means for faculty and students to interpret the efficacy of reflective approaches. Finally, study findings informed practice recommendations for the implementation of pedagogical PFR in an academic PTA program. These include affording flexibility for discussion topics, conducting student-led discussions, managing discussion frequency and group composition, and encouraging faculty participation. Keywords: Reflective practice, peer-facilitated reflection, critical thinking, physical therapy, physical therapist assistant, action research, critical incident analysi

INFLUENCES DURING STUDENT TEACHING ON PRESERVICE TEACHERS\u27 ATTITUDES TOWARD THE INCLUSION OF STUDENTS WITH DISABILITIES IN THE GENERAL EDUCATION CLASSROOM

The purpose of this research project was to explore the influences during fieldwork on preservice teachers\u27 attitudes towards the inclusion of students with disabilities in the general education classroom. An embedded, mixed-methods design was used to examine both qualitative and quantitative data. Preservice teachers completed the Opinions Relative to the Integration of Students with Disabilities (Antonak & Larrivee, 1995) survey before beginning full-time student teaching. This survey measured their attitudes towards the inclusion of students with disabilities in the general education classroom. In addition, student teachers completed the Teachers\u27 Sense of Efficacy Scale (Tschannen-Moran & Hoy, 2001) prior to their full time student teaching. During the qualitative, explanatory phase, observational, artifact, and interview data were examined from selected participants in their student teaching practicum. Participants for the qualitative phase were selected based on their initial scores on the Opinions Relative to the Integration of Students with Disabilities survey. Three special educators and three general educators who scored lowest on the scale, indicating negative attitudes about inclusive practices, were chosen to participate in the qualitative exploration. In addition, three special educators and three general educators who scored highest on the scale, indicating support for inclusion, were chosen to complete the qualitative participant group. Finally, after student teaching was completed, all participants were administered both surveys again to determine changes in attitudes responsive to their student teaching experience. Findings indicated that preservice teacher attitudes changed significantly after student teaching and that there were significant differences between special education and general education participants. Although preservice teachers\u27 self-efficacy significantly increased after fieldwork, their self-efficacy was not correlated to their attitudes about inclusion. The participants\u27 attitudes before student teaching accounted for most of their attitudes after student teaching, although the preservice teachers indicated their cooperating teacher was also very influential. Personal experience with individuals with disabilities and type of disability, severity of disability, and age of the student were all influencing factors of the preservice teachers\u27 attitudes about inclusion of students with disabilities in the general education classroom. Overall, participants\u27 attitudes fell along a continuum, with some preservice teachers ambivalent or undecided, while others were negative or positive about inclusive practices

Redefining sportspersonship : a compliant and principled model

Despite the accepted importance of sportspersonship, behaviour contrary to good sportspersonship is regularly observed in sport (Shields, Bredemeier, LaVoi, and Power, 2005). It is surprising therefore, that since the development of a multidimensional definition of sportspersonship in in mid-1990s (Vallerand, Deshaies, Cuerrier, Briere, and Pelletier, 1996; Vallerand, Briere, Blanchard, & Provencher, 1997), research into the subject has stalled somewhat. The purpose of this thesis was to reignite this avenue of research by exploring an existing model, and developing and presenting a superseding model. After a critical analysis of the existing measures of sportspersonship, the compliant and principled sportspersonship scale was developed and validated in a host of studies. Exploratory factor analysis presented an initial model of sportspersonship. This was examined using confirmatory factor analysis and exploratory structural equation modelling. A five-factor, 24-item measure of sportspersonship was presented consisting of (a) compliance towards rules, (b) compliance towards officials, (c) legitimacy of injurious acts, (d) approach towards opponent, and (e) principled game perspective.Studies in the thesis positively relate sportspersonship with moral behaviour, task goal orientation, empathy, agreeableness, and conscientiousness. It is negatively associated with antisocial behaviour and Machiavellianism. These studies support the construct validity of the scale and provide greater theoretical understanding of sportspersonship. Criterion validity is supported through two experimental studies that found that sportspersonship positively predicted prosocial and negatively predicted cheating. Finally, recommendations for enhancing sportspersonship are offered. Overall, the thesis redefines sportspersonship, presents a new multidimensional measure of sportspersonship and evidence of its validity, explores the relationship of sportspersonship to other psychological concepts, and provides a template for assessing and developing measurement scales