Simple but effective feedback generation to tutor abstract problem solving Xin Lu author Barbara Di Eugenio author Stellan Ohlsson author Davide Fossati author 2008-06 text Proceedings of the Fifth International Natural Language Generation Conference Michael White editor Crystal Nakatsu editor David McDonald editor Association for Computational Linguistics Salt Fork, Ohio, USA conference publication lu-etal-2008-simple https://aclanthology.org/W08-1114/ 2008-06 104 112