A Robust Reputation-Based Group Ranking System and Its Resistance to Bribery

• Type: Article in International Scientific Journal
• Date: 2022

Authors

João Saúde (Author) Other; Guilherme Ramos (Author) FEUP; Ludovico Boratto (Author) Other; Carlos Caleiro (Author) Other

Journal

Title: ACM Transactions on Knowledge Discovery from Data

Vol. 16 No. 2

Pages: 26:1-26:35

ISSN: 1556-4681

Publisher: ACM

Other information

Authenticus ID: P-00V-FQ7

DOI: 10.1145/3462210

Abstract (EN): The spread of online reviews and opinions and its growing influence on people's behavior and decisions boosted the interest to extract meaningful information from this data deluge. Hence, crowdsourced ratings of products and services gained a critical role in business and governments. Current state-of-the-art solutions rank the items with an average of the ratings expressed for an item, with a consequent lack of personalization for the users, and the exposure to attacks and spamming/spurious users. Using these ratings to group users with similar preferences might be useful to present users with items that reflect their preferences and overcome those vulnerabilities. In this article, we propose a new reputation-based ranking system, utilizing multipartite rating subnetworks, which clusters users by their similarities using three measures, two of them based on Kolmogorov complexity. We also study its resistance to bribery and how to design optimal bribing strategies. Our system is novel in that it reflects the diversity of preferences by (possibly) assigning distinct rankings to the same item, for different groups of users. We prove the convergence and efficiency of the system. By testing it on synthetic and real data, we see that it copes better with spamming/spurious users, being more robust to attacks than state-of-the-art approaches. Also, by clustering users, the effect of bribery in the proposed multipartite ranking system is dimmed, comparing to the bipartite case.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 35