Dynamic Key-Value Memory Networks for Knowledge Tracing

TL;DR

This paper introduces Dynamic Key-Value Memory Networks (DKVMN), a novel model for Knowledge Tracing that effectively models student knowledge states and relationships between concepts, outperforming previous methods.

Contribution

The paper proposes DKVMN, a new neural network model with static keys and dynamic values for improved knowledge tracing and concept discovery.

Findings

Outperforms state-of-the-art models on multiple datasets

Automatically discovers underlying concepts without human annotations

Depicts evolving student knowledge states accurately

Abstract

Knowledge Tracing (KT) is a task of tracing evolving knowledge state of students with respect to one or more concepts as they engage in a sequence of learning activities. One important purpose of KT is to personalize the practice sequence to help students learn knowledge concepts efficiently. However, existing methods such as Bayesian Knowledge Tracing and Deep Knowledge Tracing either model knowledge state for each predefined concept separately or fail to pinpoint exactly which concepts a student is good at or unfamiliar with. To solve these problems, this work introduces a new model called Dynamic Key-Value Memory Networks (DKVMN) that can exploit the relationships between underlying concepts and directly output a student's mastery level of each concept. Unlike standard memory-augmented neural networks that facilitate a single memory matrix or two static memory matrices, our model has one static matrix called key, which stores the knowledge concepts and the other dynamic matrix called value, which stores and updates the mastery levels of corresponding concepts. Experiments show that our model consistently outperforms the state-of-the-art model in a range of KT datasets. Moreover, the DKVMN model can automatically discover underlying concepts of exercises typically performed by human annotations and depict the changing knowledge state of a student.