Behavior Analysis through Reputation Propagation in a Multi-Context Environment Ebrahim Bagheri and Ali A. Ghorbani E.Bagheri@unb.ca and Ghorbani@unb.ca Faculty of Computer Science - University of New Brunswick 1/18/2019

Reputation Reputation is a : It can be ascribed to a distributed, socially ascribed, and collective belief of the society towards a single identity. It can be ascribed to a single person, group, role or even a non-human character. 1/18/2019

Reputation Ascription Reputation owners are affected by the status of their reputation. But have no control over the accredited reputation. Affecting reputation ascription through self alignment with social norms. 1/18/2019

Reputation Inheritance Assignment of reputation to a certain group of people, roles or objects A rough estimation of a typical group member’s reputation. This helps overcome reputation calculation for the unknown people to the society. 1/18/2019

Reputation Inheritance (cntd.) Inheritance of reputation in a group setting (Dis)improvement of the status of the members based the group’s reputation Members affect the group’s reputation based on their social image. 1/18/2019

Reputation in Virtual Environments Interactions in a virtual environment based on reputation values. Interaction among users based on reputation and trust reputation is taken for granted since: it has been communally calculated and ascribed. Reputation based systems should observe: Identity Continuity and Reputation Ubiquity. 1/18/2019

Identity Continuity & Reputation Ubiquity avoiding change of the identity or the use of pseudonyms because: It results in history clearance and false reputation declaration. “Reputation ubiquity” allows universal reputation values users cannot hide their real identity 1/18/2019

Reputation Nuclei R Role Fulfillment Relationship Knowledge Experience Credential Competence Honesty Favorability Faith 1/18/2019

Reputation Formalization Creating social norms based on these factors. Creation of context dependent reputation calculation models 1/18/2019

Reputation in a Single Context Reputation has been mostly formalized in a specific context. Because of the underlying social values of each society For example in academia, for a prof. reputation is: his/her publications, teaching experience and credentials; But in the business community: industrial experience, trading knowledge, and Social relationships are more important than other factors. 1/18/2019

Mutual Effect of Different Contexts on Reputation Reputation is affected by the other contexts People with high reputation values in a specific context, will be looked upon as successful else where. The opposite situation is also true. Mutual effect of different contexts cannot be overlooked. 1/18/2019

Reputation in Multiple Context 1 2 3 4 R Role Fulfillment Relationship Knowledge Experience Credential Competence Honesty Favorability Faith Overall Reputation Reputation in Multiple Context 1/18/2019

Reputation Inference Understanding the position of a person in a new context People carry their reputation with them into new contexts This does not determine exactly the ultimate reputation of that person But it is a good initial estimation The person can later improve or damage his reputation 1/18/2019

Inter-context Reputation Migration We propose two steps for reputation migration: Forward update mechanism Backward reputation adjustment method 1/18/2019

Forward Update Mechanism 1 2 3 4 C1 Reputation Change 1/18/2019

Backward Adjustment Mechanism 1 2 Backward Adjustment Mechanism 3 4 NIC=8 NIC=4 NICi is calculated and shows the number of interactions that a person has in Context i. 1/18/2019

Scenarios Four Scenarios: Consistent Homogeneous Reputation High-Consistent Heterogeneous Reputation Low-Consistent Heterogeneous Reputation Varying Heterogeneous Reputation 1/18/2019

Observations 1/18/2019

Observations 1/18/2019

Conclusions Reputation is a context specific socially ascribed value. A specific reputation formalization cannot be applied to multiple contexts This prevents reputation inference in multiple contexts. Here we propose a reputation propagation scheme. The proposed model provides: A rough anticipation of users’ behavior in new contexts Analysis of reputation change in multiple contexts 1/18/2019

Thank you for your patience. 1/18/2019