基于大语言模型的多知识视角问答社区专家发现模型

Large Language Model-based Multi-knowledge Perspective Expert Finding Model

  • 摘要: 专家发现(Expert Finding)的核心目标在于精准匹配用户提问与能够提供高质量解答的潜在专家,是问答社区、企业搜索和社交网络等多种应用的核心支撑任务。然而,当前专家发现领域的研究大多局限于单一核心知识视角,难以全面、多视角捕捉问题和专家的潜在特性,从而限制了专家发现的准确性。为解决这一难题,文章提出了一种基于大语言模型的多知识视角专家发现模型(LLMef)。该模型引入了多知识视角建模机制,有效融合核心知识、前置知识及后置知识三大视角的全面信息,实现对问题和专家特征的深度、细粒度表征。具体而言,LLMef模型基于开源大语言模型LLaMA-2-7B设计问题多知识视角编码器,实现问题的多知识视角表征;同时,设计了专家多知识视角聚合器,利用注意力机制聚合专家历史回答问题中的多知识视角信息,生成专家的多知识视角聚合表征。最后,通过对比实验、消融实验、参数敏感性实验,并辅以案例分析对LLMef模型进行验证。对比实验结果表明:与最好的基线模型TCQR相比,LLMef模型在6个公开数据集上的平均倒数排名(MRR)、前K精确度(P@ K)和归一化折损累积增益(NDCG)分别平均提升了9.83%、13.58%、6.25%。消融实验结果表明问题多知识视角编码器和专家多知识视角聚合器的协同作用显著提升了问题建模与专家建模的精细度及准确性:与LLMef模型相比,关于问题多知识视角编码器的变体模型的MRR值平均降低了7.21%,关于专家多知识视角聚合器的变体模型的MRR值平均降低了10.43%。此外,参数敏感性实验结果明确了LLMef模型的最优参数配置,案例分析结果进一步揭示了LLMef模型优化专家发现效果的内在逻辑。综上可知,LLMef模型能够更精准地挖掘问题与专家间的潜在知识关联,可为问答社区、企业搜索等场景提供更可靠的专家发现结果。

     

    Abstract: Expert finding aims to accurately match user questions with potential experts who can provide high-qua-lity answers, serving as a core task that supports various applications such as question and answering (Q&A) communities, enterprise search, and social networks. However, current research methods are limited to a single core knowledge perspective, making it difficult to comprehensively capture the potential characteristics of questions and experts from multiple perspectives, thereby restricting the accuracy of expert finding. To address this issue, a Large Language Model-based Multi-knowledge Perspective expert finding Model (LLMef) has been proposed. The LLMef model constructs a multi-knowledge perspective modeling mechanism, effectively integrating comprehensive information from three perspectives: core knowledge, prerequisite knowledge, and advanced knowledge, achieving deep and fine-grained representation of questions and experts. Specifically, the LLMef model designs a Question Multi-Knowledge perspective (QMK) encoder for questions based on open source large language model LLaMA-2-7B, enabling the representation of questions from multiple knowledge perspectives. Additionally, it designs an Expert Multi-Knowledge perspective (EMK) aggregator for experts, utilizing an attention mechanism to aggregate multi-knowledge perspective information from experts' historically answered questions, generating a multi-know-ledge perspective aggregated representation of experts. The cooperation of QMK and EMK significantly improves the precision of question and expert modeling. To validate the LLMef model, comparative experiments, ablation experiments, and parameter sensitivity experiments are conducted in the paper, with case studies also supplemented. The results of the comparative experiments demonstrate that the LLMef model has achieved average improvements of 9.83%, 13.58%, and 6.25% in Mean Reciprocal Rank (MRR), Precision@ K (P@ K), and Normalized Discounted Cumulative Gain (NDCG) metrics, respectively, across six public datasets, compared to the best-performing baseline TCQR. In the ablation experiments, compared with the original LLMef model, the MRR metric of the variant models removing the Question Multi-Knowledge Perspective Encoder (QMK) decreases by an average of 7.21%, while that of the variant models removing the Expert Multi-Knowledge Perspective Aggregator (EMK) decreases by an average of 10.43%. In addition, the optimal parameter configuration of the LLMef model is determined through parameter sensitivity experiments, and the internal logic of LLMef in optimizing expert finding performance is further revealed with the help of case studies. The experimental results demonstrate that the LLMef mo-del can more precisely capture the latent knowledge associations between questions and experts, thereby delivering more reliable expert finding outcomes for practical scenarios including Q&A communities and enterprise search systems.

     

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