Martínez-Plumed, F., D. Castellano, C. Monserrat-Aranda, and J. Hernández-Orallo. “When AI Difficulty Is Easy: The Explanatory Power of Predicting IRT Difficulty”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 36, no. 7, June 2022, pp. 7719-27, doi:10.1609/aaai.v36i7.20739.