基于学习迁移的稳定知识追踪模型

A Stable Knowledge Tracing Model Based on Learning Transfers

  • 摘要: 知识追踪基于历史交互日志估计学生在每个时间步上的知识状态,从而预测学生在求解新练习时的答题表现,是智能教学系统的核心功能。针对现有的知识追踪方法未考虑学生的单个概念知识状态和学生的整体知识状态在相邻时间步之间稳定演变的问题,文章提出了一种基于学习迁移的稳定知识追踪模型(SKT-LT):一方面,利用知识概念间的学习迁移效应来优化知识追踪过程;另一方面,通过在知识追踪过程中引入学生的单概念知识状态的稳定性约束和学生的整体知识状态的稳定性约束来确保模型预测的知识状态在相邻时间步不发生突变,从而提升模型的预测准确性。最后,在2个公开数据集(ASSISTments 2015和ASSISTments 2009)上,将SKT-LT模型与DKT、CKT、ContextKT、DKVMN、SPARSEKT、GKT、SKT模型进行对比实验。对比实验结果表明:SKT-LT模型在ASSISTments 2015数据集上的AUC值和F1-Score值分别比表现最好的基线模型(SKT)提升了3.45%、22.80%。同时,消融实验证明了SKT-LT模型中各个模块的有效性,而可视化实验则证明了SKT-LT模型能够追踪到稳定演变的学生知识状态。

     

    Abstract: Knowledge Tracing (KT) is the core function of intelligent tutoring systems. It estimates the knowledge states of a student on each time step based on historical interaction logs, and then predicts the student's perfor-mance in solving new exercises. A stable knowledge tracing model based on learning transfer (SKT-LT) is proposed to address the problem of existing knowledge tracing methods not considering the stable evolution of students' individual concept knowledge states and overall knowledge states between adjacent time steps. On the one hand, the learning transfer effect between knowledge concepts is utilized to optimize the knowledge tracing process. On the other hand, by introducing the stability constraint of single concept knowledge state of student and the stability constraint of overall knowledge state of student in the knowledge tracing process, the predicted knowledge state of the model does not underwent abrupt changes in adjacent time steps, thereby improving the accuracy of the model's predictions. Finally, comparative experiments were conducted between the SKT-LT model and the DKT, CKT, ContextKT, DKVMN, SPARSEKT, GKT, and SKT models on two publicly available datasets (ASSISTments 2015 and ASSISTments 2009). The experimental results show that the AUC and F1-Score values of the SKT-LT model on the ASSISTments 2015 dataset improved by 3.45% and 22.80%, respectively, compared to the best performing baseline model SKT. Meanwhile, ablation experiments demonstrate the effectiveness of each module in the SKT-LT model, while visualization experiments have shown that the SKT-LT model can trace stable students' knowledge states.

     

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