The integration of language models in the legal domain holds considerable promise for streamlining processes and improving efficiency in managing extensive workloads. However, the specialized terminology, nuanced language, and formal style of legal texts can present substantial challenges. This study examines whether preference-based training techniques, specifically Reinforcement Learning from Human Feedback and Direct Preference Optimization, can enhance models’ performance in generating Icelandic legal summaries that align with domain-specific language standards and user preferences. We compare models fine-tuned with preference training to those using conventional supervised learning. Results indicate that preference training improves the legal accuracy of generated summaries over standard fine-tuning but does not significantly enhance the overall quality of Icelandic language usage. Discrepancies between automated metrics and human evaluations further underscore the importance of qualitative assessment in developing language models for the legal domain.

We experiment with sentiment classification models for Icelandic that leverage machine-translated data for training. Since no large sentiment dataset exists for Icelandic, we translate 50,000 English IMDb reviews, classified either as positive or negative, into Icelandic using two services: Google Translate and GreynirTranslate. After machine translation, we assess whether the sentiment of the source language text is retained in the target language. Moreover, we evaluate the accuracy of the sentiment classifiers on non-translated Icelandic text.The performance of three types of baseline classifiers is compared, i.e., Support Vector Machines, Logistic Regression and Naive Bayes, when trained on translated data generated by either translation service. Furthermore, we fine-tune and evaluate three pre-trained transformer-based models, RoBERTa, IceBERT and ELECTRA, on both the original English texts and the translated texts. Our results indicate that the transformer models perform better than the baseline classifiers on all datasets. Moreover, our evaluation shows that the transformer models trained on data translated from English reviews can be used to effectively classify sentiment on non-translated Icelandic movie reviews.