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Triple Factor-aware Task Recommendation for Crowdsourced Q&A Services
PhD Thesis Proposal Defence Title: "Triple Factor-aware Task Recommendation for Crowdsourced Q&A Services" by Mr. Zheng LIU Abstract: Task Recommendation (TR) is one of the most important functions for crowdsourced Q&A services. Specifically, given a set of tasks to be solved, TR identifies certain groups of workers whom are expected to give timely answers with high qualities, and recommend the presented tasks to corresponding workers. To address the TR problem, recent studies have introduced a number of recommendation approaches, which take advantage of workers' expertises or preferences towards different types of tasks. However, without a thorough consideration of workers' characters, such approaches will lead to either inadequate task fulfillment or inferior answer quality. In this work, we propose the Triple-factor Aware Task Recommendation framework, which collectively considers workers' expertises, preferences and activenesses to maximize the overall production of high quality answers. We construct the Latent Hierarchical Factorization Model, which is able to infer the tasks' underlying categories and workers' latent characters from the historical data; and we propose a novel parameter inference method, which only requires the processing of positive instances, giving rise to significantly higher time efficiency and better inference quality. What's more, the online greedy and offline sampling-based algorithms are developed for the stream-scenario and batch-scenario, where tasks are processed in a stream and in a batch, respectively. With the adoption of both algorithms, near-optimal recommendation results can be acquired with considerably reduced time consumption. Comprehensive experiments have been carried out using both real and synthetic datasets, whose results verify the effectiveness and efficiency of our proposed methods. Date: Thursday, 22 March 2018 Time: 10:30am - 12:30pm Venue: Room 3494 (lifts 25/26) Committee Members: Prof. Lei Chen (Supervisor) Dr. Yangqiu Song (Chairperson) Dr. Wei Wang Dr. Raymond Wong **** ALL are Welcome ****