Stefan Keller
2026
Through the Sentence Lens: Explainable Essay Scoring through Fine-Grained Predictions
Daniel Mora Melanchthon | Stefan Keller | Andrea Horbach
Proceedings of the 21st Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2026)
Daniel Mora Melanchthon | Stefan Keller | Andrea Horbach
Proceedings of the 21st Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2026)
Beyond performance, model transparency is a crucial factor in Automated Essay Scoring, yet current systems often lack explainability, limiting their pedagogical value and users’ trust. Existing explainability methods, such as gradient-based attribution or feature-importance approaches, either produce counterintuitive explanations or are too complex for classroom use. To address this limitation, we make use of fine-grained prediction at the sentence level as a way to enhance explainability. We propose ablation strategies to derive sentence-level pseudo scores from essay-level gold scores and use them to train sentence-level models. We evaluate their performance against essay-level baselines on two datasets (ASAP and MEWS), and compare their sentence-level output to a human baseline. Results indicate a trade-off between essay-level performance and sentence-level granularity. For the language quality trait, most sentence-level models achieve performance comparable to the essay-level baseline, whereas for content, the approach yields more positive results on prompts with shorter
2023
Sequence Tagging in EFL Email Texts as Feedback for Language Learners
Yuning Ding | Ruth Trüb | Johanna Fleckenstein | Stefan Keller | Andrea Horbach
Proceedings of the 12th Workshop on NLP for Computer Assisted Language Learning
Yuning Ding | Ruth Trüb | Johanna Fleckenstein | Stefan Keller | Andrea Horbach
Proceedings of the 12th Workshop on NLP for Computer Assisted Language Learning
2022
Bringing Automatic Scoring into the Classroom - Measuring the Impact of Automated Analytic Feedback on Student Writing Performance
Andrea Horbach | Ronja Laarmann-Quante | Lucas Liebenow | Thorben Jansen | Stefan Keller | Jennifer Meyer | Torsten Zesch | Johanna Fleckenstein
Proceedings of the 11th Workshop on NLP for Computer Assisted Language Learning
Andrea Horbach | Ronja Laarmann-Quante | Lucas Liebenow | Thorben Jansen | Stefan Keller | Jennifer Meyer | Torsten Zesch | Johanna Fleckenstein
Proceedings of the 11th Workshop on NLP for Computer Assisted Language Learning