Leveraging peer communication to enhance crowdsourcing

Crowdsourcing has become a popular tool for large-scale data collection where it is often assumed that crowd workers complete the work independently. In this paper, we relax such independence property and explore the usage of peer communication-a kind of direct interactions between workers-in crowdsourcing. In particular, in the crowdsourcing setting with peer communication, a pair of workers are asked to complete the same task together by first generating their initial answers to the task independently and then freely discussing the task with each other and updating their answers after the discussion. We first experimentally examine the effects of peer communication on individual microtasks. Our results conducted on three types of tasks consistently suggest that work quality is significantly improved in tasks with peer communication compared to tasks where workers complete the work independently. We next explore how to utilize peer communication to optimize the requester's total utility while taking into account higher data correlation and higher cost introduced by peer communication. In particular, we model the requester's online decision problem of whether and when to use peer communication in crowdsourcing as a constrained Markov decision process which maximizes the requester's total utility under budget constraints. Our proposed approach is empirically shown to bring higher total utility compared to baseline approaches.