Worker similarity-based noise correction for crowdsourcing

Crowdsourcing offers a cost-effective way to obtain multiple noisy labels for each instance by employing multiple crowd workers. Then label integration is used to infer its integrated label. Despite the effectiveness of label integration algorithms, there always remains a certain degree of noise in the integrated labels. Thus noise correction algorithms have been proposed to reduce the impact of noise. However, almost all existing noise correction algorithms only focus on individual workers but ignore the correlations among workers. In this paper, we argue that similar workers have similar annotating skills and tend to be consistent in annotating same or similar instances. Based on this premise, we propose a novel noise correction algorithm called worker similarity-based noise correction (WSNC). At first, WSNC exploits the annotating information of similar workers on similar instances to estimate the quality of each label annotated by each worker on each instance. Then, WSNC re-infers the integrated label of each instance based on the qualities of its multiple noisy labels. Finally, WSNC considers the instance whose re-inferred integrated label differs from its original integrated label as a noise instance and further corrects it. The extensive experiments on a large number of simulated and three real-world crowdsourced datasets verify the effectiveness of WSNC.