Fault-Tolerant Entity Resolution with the Crowd

In recent years, crowdsourcing is increasingly applied as a means to enhance data quality. Although the crowd generates insightful information especially for complex problems such as entity resolution (ER), the output quality of crowd workers is often noisy. That is, workers may unintentionally generate false or contradicting data even for simple tasks. The challenge that we address in this paper is how to minimize the cost for task requesters while maximizing ER result quality under the assumption of unreliable input from the crowd. For that purpose, we first establish how to deduce a consistent ER solution from noisy worker answers as part of the data interpretation problem. We then focus on the next-crowdsource problem which is to find the next task that maximizes the information gain of the ER result for the minimal additional cost. We compare our robust data interpretation strategies to alternative state-of-the-art approaches that do not incorporate the notion of fault-tolerance, i.e., the robustness to noise. In our experimental evaluation we show that our approaches yield a quality improvement of at least 20% for two real-world datasets. Furthermore, we examine task-to-worker assignment strategies as well as task parallelization techniques in terms of their cost and quality trade-offs in this paper. Based on both synthetic and crowdsourced datasets, we then draw conclusions on how to minimize cost while maintaining high quality ER results.