Elo-based learner modeling for the adaptive practice of facts

We investigate applications of learner modeling in a computerized adaptive system for practicing factual knowledge. We focus on areas where learners have widely varying degrees of prior knowledge. We propose a modular approach to the development of such adaptive practice systems: dissecting the system design into an estimation of prior knowledge, an estimation of current knowledge, and the construction of questions. We provide a detailed discussion of learner models for both estimation steps, including a novel use of the Elo rating system for learner modeling. We implemented the proposed approach in a system for practising geography facts; the system is widely used and allows us to perform evaluation of all three modules. We compare the predictive accuracy of different learner models, discuss insights gained from learner modeling, as well as the impact different variants of the system have on learners’ engagement and learning.