Francisco Castro
2026
The Effects of Structured LLM-Generated Feedback on Programming Assignment Performance
Tsvetomila Mihaylova | Evanfiya Logacheva | Arto Hellas | Jing Fan | Francisco Castro | Bita Akram | Narges Norouzi | Peter Brusilovsky | Juho Leinonen
Proceedings of the 21st Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2026)
Tsvetomila Mihaylova | Evanfiya Logacheva | Arto Hellas | Jing Fan | Francisco Castro | Bita Akram | Narges Norouzi | Peter Brusilovsky | Juho Leinonen
Proceedings of the 21st Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2026)
When programming students encounter errors in their code, compiler messages or static analysis output often provide limited guidance, particularly for novice programmers. Personalized feedback from instructors can be effective but does not scale well. Recent advances in large language models (LLMs) enable automated feedback generation at scale.This study examines whether LLM-generated feedback with different levels of guidance is associated with differences in students’ problem-solving behavior. We analyze effects on time to solution and number of attempts, and examine whether these effects differ by programming experience. We design three feedback types and compare them to a baseline in which students receive only compiler error messages. Results from an online programming course show that LLM-generated feedback is associated with faster time to solution compared to the no-feedback baseline, with less guided feedback showing slightly stronger effects. Overall, the findings suggest that feedback structure plays an important role in how students progress toward correct solutions and motivate further work on adaptive feedback designs and longer-term learning outcomes.
2010
The RODRIGO Database
Nicolas Serrano | Francisco Castro | Alfons Juan
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)
Nicolas Serrano | Francisco Castro | Alfons Juan
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)
Annotation of digitized pages from historical document collections is very important to research on automatic extraction of text blocks, lines, and handwriting recognition. We have recently introduced a new handwritten text database, GERMANA, which is based on a Spanish manuscript from 1891. To our knowledge, GERMANA is the first publicly available database mostly written in Spanish and comparable in size to standard databases. In this paper, we present another handwritten text database, RODRIGO, completely written in Spanish and comparable in size to GERMANA. However, RODRIGO comes from a much older manuscript, from 1545, where the typical difficult characteristics of historical documents are more evident. In particular, the writing style, which has clear Gothic influences, is significantly more complex than that of GERMANA. We also provide baseline results of handwriting recognition for reference in future studies, using standard techniques and tools for preprocessing, feature extraction, HMM-based image modelling, and language modelling.