Okan Bulut


2025

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Enhancing Essay Scoring with GPT-2 Using Back Translation Techniques
Aysegul Gunduz | Mark Gierl | Okan Bulut
Proceedings of the Artificial Intelligence in Measurement and Education Conference (AIME-Con): Full Papers

This study evaluates GPT-2 (small) for automated essay scoring on the ASAP dataset. Back-translation (English–Turkish–English) improved performance, especially on imbalanced sets. QWK scores peaked at 0.77. Findings highlight augmentation’s value and the need for more advanced, rubric-aware models for fairer assessment.

2024

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Item Difficulty and Response Time Prediction with Large Language Models: An Empirical Analysis of USMLE Items
Okan Bulut | Guher Gorgun | Bin Tan
Proceedings of the 19th Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2024)

This paper summarizes our methodology and results for the BEA 2024 Shared Task. This competition focused on predicting item difficulty and response time for retired multiple-choice items from the United States Medical Licensing Examination® (USMLE®). We extracted linguistic features from the item stem and response options using multiple methods, including the BiomedBERT model, FastText embeddings, and Coh-Metrix. The extracted features were combined with additional features available in item metadata (e.g., item type) to predict item difficulty and average response time. The results showed that the BiomedBERT model was the most effective in predicting item difficulty, while the fine-tuned model based on FastText word embeddings was the best model for predicting response time.