A Misreport- and Collusion-Proof Crowdsourcing Mechanism without Quality Verification

TL;DR

This paper introduces a new crowdsourcing mechanism that ensures truthful quality reporting and prevents collusion without needing to verify task quality, improving scalability and strategic planning.

Contribution

It presents a novel misreport- and collusion-proof mechanism that controls quality without verification, revealing counterintuitive insights about worker behavior and requestor utility.

Findings

High-quality workers may pretend to be low-quality.

Increasing task quality does not always benefit the requestor.

More workers do not necessarily increase the requestor's utility.

Abstract

Quality control plays a critical role in crowdsourcing. The state-of-the-art work is not suitable for large-scale crowdsourcing applications, since it is a long haul for the requestor to verify task quality or select professional workers in a one-by-one mode. In this paper, we propose a misreport- and collusion-proof crowdsourcing mechanism, guiding workers to truthfully report the quality of submitted tasks without collusion by designing a mechanism, so that workers have to act the way the requestor would like. In detail, the mechanism proposed by the requester makes no room for the workers to obtain profit through quality misreport and collusion, and thus, the quality can be controlled without any verification. Extensive simulation results verify the effectiveness of the proposed mechanism. Finally, the importance and originality of our work lie in that it reveals some interesting and even counterintuitive findings: 1) a high-quality worker may pretend to be a low-quality one; 2) the rise of task quality from high-quality workers may not result in the increased utility of the requestor; 3) the utility of the requestor may not get improved with the increasing number of workers. These findings can boost forward looking and strategic planning solutions for crowdsourcing.