Hierarchical Multi-Armed Bandits for the Concurrent Intelligent Tutoring of Concepts and Problems of Varying Difficulty Levels
Blake Castleman, Uzay Macar, Ansaf Salleb-Aouissi
TL;DR
This work addresses the need for open-source, adaptive tutoring systems capable of concurrently steering learners through conceptual ideas and associated problems with varying difficulty. It proposes a deployable hierarchical MAB architecture consisting of a high-level concept MAB and a low-level problem MAB, guided by ZPDES and memory-decay modeling (MCM) and augmented with MAPLE-inspired transient difficulty ranking. Bayesian Knowledge Tracing simulations show that a difficulty-agnostic hierarchical MAB improves mastery, and adding problem difficulty adaptation yields additional gains, indicating practical benefits for remote education. By delivering an open-source platform and detailed parameterizations, the paper enables researchers and educators to implement and extend MAB-based tutoring pipelines in real-world settings, with future work focusing on real-world trials, dynamic difficulty updates, and material redirects for underperforming students.
Abstract
Remote education has proliferated in the twenty-first century, yielding rise to intelligent tutoring systems. In particular, research has found multi-armed bandit (MAB) intelligent tutors to have notable abilities in traversing the exploration-exploitation trade-off landscape for student problem recommendations. Prior literature, however, contains a significant lack of open-sourced MAB intelligent tutors, which impedes potential applications of these educational MAB recommendation systems. In this paper, we combine recent literature on MAB intelligent tutoring techniques into an open-sourced and simply deployable hierarchical MAB algorithm, capable of progressing students concurrently through concepts and problems, determining ideal recommended problem difficulties, and assessing latent memory decay. We evaluate our algorithm using simulated groups of 500 students, utilizing Bayesian Knowledge Tracing to estimate students' content mastery. Results suggest that our algorithm, when turned difficulty-agnostic, significantly boosts student success, and that the further addition of problem-difficulty adaptation notably improves this metric.
