融合遗忘机制的多模态知识追踪模型  

Multimodality and Forgetting Mechanisms Model for Knowledge Tracing

作　　者：闫秋艳[1] 孙浩 司雨晴 袁冠[1] YAN Qiuyan;SUN Hao;SI Yuqing;YUAN Guan(School of Computer Science&Technology,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学计算机科学与技术学院,江苏徐州221116

出　　处：《计算机科学》2024年第7期133-139,共7页Computer Science

基　　金：国家自然科学基金(61977061,62277046)。

摘　　要：知识追踪是构建自适应教育系统的核心和关键,常被用以捕获学生的知识状态、预测学生的未来表现。以往的知识追踪模型仅根据结构信息对问题、技能进行建模,无法利用问题、技能的多模态信息构造其相互依赖关系。同时,关于学生的记忆水平仅以时间做量化,未考虑不同模态对记忆水平的影响。因此,提出了融合遗忘机制的多模态知识追踪模型。首先,对问题、技能节点,以图文匹配作为训练任务优化单模态嵌入,并通过计算多模态融合后节点间的相似度,获得问题和技能的关联权重从而计算生成问题节点的嵌入。其次,通过长短期记忆网络获取带有遗忘因素的学生知识状态,并将其融入学生的答题记录中生成学生节点的嵌入。最后,根据学生的答题次数和不同模态的有效记忆率计算学生和问题间的关联强度,通过图注意力网络进行信息传播,预测学生对不同问题的答题情况。在两个真实课堂自采数据集上进行了对比实验和消融实验,结果表明所提方法比其他基于图的知识追踪模型具有更好的预测精度,且针对多模态和遗忘机制的设计能有效提升原始模型的预测效果。同时,通过对一个具体案例的可视化分析,进一步说明了所提方法的实际应用效果。Knowledge tracing is the core and key to build an adaptive education system,and it is often used to capture students’knowledge states and predict their future performance.Previous knowledge tracing models only model questions and skills based on structural information,unable to utilize the multimodal information of questions and skills to construct their interdependence.Additionally,the memory level of students is only quantified by time,without considering the influence of different modalities.Therefore,a multimodality and forgetting mechanisms model for knowledge tracing(MFKT)is proposed.Firstly,for question and skill nodes,a image-text matching task is used to optimize the unimodal embedding,and obtain the association weight calculation of questions and skills by calculating the similarity between nodes after multimodal fusion to generate the embedding of question nodes.Secondly,the student’s knowledge state is obtained through the long short-term memory network,and forgetting factors are incorporated into their response records to generate student embeddings.Finally,the correlation strength between students and questions is calculated based on the student’s response frequency and the effective memory rate of different modalities.Information propagation is performed using a graph attention network to predict the student’s response to different questions.Comparative experiments and ablation experiments on two real classroom self-collected datasets show that our method has better prediction accuracy compared to other graph-based knowledge tracing models,and the design of multimodality and forgetting mechanisms effectively improves the prediction performance of the original model.At the same time,through the visual analysis of a specific case,further illustrate the practical application effect of this method.

关 键 词：知识追踪 多模态 异质图 遗忘机制 

分 类 号：G40-057[文化科学—教育学原理]