Interpreting model discovery and testing generalization to a new dataset.
Ran Liu, Elizabeth A. McLaughlin, Kenneth R. Koedinger · 2014
Automated techniques have proven useful for improving models of student learning even beyond the best human-generated models. There has been concern among the EDM community about whether small prediction improvements matter. We argue that they can be quite significant when they are interpretable and actionable, but the importance of generating meaningful, validated, and generalizable interpretations from machine-model discoveries has been under-emphasized in educational data mining. Here, we interpret a Learning Factors Analysis model discovery from a geometry dataset to suggest that students experienced difficulty applying the square root operation in circle-area backward problem steps. We then sought to validate and generalize this interpretation in the context of a completely novel dataset. Results indicated that our interpretation of the small, automated prediction improvement not only held up in the context of a novel dataset but also generalized to new types of problems that didn’t exist in the original dataset. We argue that identifying cognitive interpretations of automated model discoveries and assessing the generalizability of such interpretations are critical to translating those model discoveries to concrete improvements in instructional design.