SAICL: Student Modelling with Interaction-level Auxiliary Contrastive Tasks for Knowledge Tracing and Dropout Prediction

Knowledge tracing and dropout prediction are crucial for online education to estimate students’ knowledge states or to prevent dropout rates. While traditional systems interacting with students suffered from data sparsity and overfitting, recent sample-level contrastive learning helps to alleviate this issue. One major limitation of sample-level approaches is that they regard students’ behavior interaction sequences as a bundle, so they often fail to encode temporal contexts and track their dynamic changes, making it hard to find optimal representations for knowledge tracing and dropout prediction. To apply temporal context within the sequence, this study introduces a novel student modeling framework, SAICL: $\mathbf{\text{s}}$tudent modeling with $\mathbf{\text{a}}$uxiliary $\mathbf{\text{i}}$nteraction-level $\mathbf{\text{c}}$ontrastive $\mathbf{\text{l}}$earning. In detail, SAICL can utilize both proposed self-supervised/supervised interaction-level contrastive objectives: MilCPC ($\mathbf{\text{M}}$ulti-$\mathbf{\text{I}}$nteraction-$\mathbf{\text{L}}$evel $\mathbf{\text{C}}$ontrastive $\mathbf{\text{P}}$redictive $\mathbf{\text{C}}$oding) and SupCPC ($\mathbf{\text{Sup}}$ervised $\mathbf{\text{C}}$ontrastive $\mathbf{\text{P}}$redictive $\mathbf{\text{C}}$oding). While previous sample-level contrastive methods for student modeling are highly dependent on data augmentation methods, the SAICL is free of data augmentation while showing better performance in both self-supervised and supervised settings. By combining cross-entropy with contrastive objectives, the proposed SAICL achieved comparable knowledge tracing and dropout prediction performance with other state-of-art models without compromising inference costs.