Performance Evaluation of Transformer-Based Pre-Trained Language Models for Turkish Question-Answering

Natural language processing (NLP) has made significant progress with the introduction of Transformer-based architectures that have revolutionized tasks such as question-answering (QA). While English is a primary focus of NLP research due to its high resource datasets, low-resource languages such as Turkish present unique challenges such as linguistic complexity and limited data availability. This study evaluates the performance of Transformer-based pre-trained language models on QA tasks and provides insights into their strengths and limitations for future improvements. In the study, using the SQuAD-TR dataset, which is the machine-translated Turkish version of the SQuAD 2.0 dataset, variations of the mBERT, BERTurk, ConvBERTurk, DistilBERTurk, and ELECTRA Turkish pre-trained models were fine-tuned. The performance of these fine-tuned models was tested using the XQuAD-TR dataset. The models were evaluated using Exact Match (EM) Rate and F1 Score metrics. Among the tested models, the ConvBERTurk Base (cased) model performed the best, achieving an EM Rate of 57.81512% and an F1 Score of 71.58769%. In contrast, the DistilBERTurk Base (cased) and ELECTRA TR Small (cased) models performed poorly due to their smaller size and fewer parameters. The results indicate that case-sensitive models generally perform better than case-insensitive models. The ability of case-sensitive models to discriminate proper names and abbreviations more effectively improved their performance. Moreover, models specifically adapted for Turkish performed better on QA tasks compared to the multilingual mBERT model.