@inproceedings{ITICSE2015, author="Bellettini, Carlo and Lonati, Violetta and Malchiodi, Dario and Monga, Mattia and Morpurgo, Anna and Torelli, Mauro", title="How Challenging are Bebras Tasks? An IRT analysis based on the performance of Italian students", booktitle="ITiCSE '15 Proceedings of the 2015 ACM Conference on Innovation and Technology in Computer Science Education", address="New York", publisher="ACM",pages="27-32", year=2015},