The goal of our study is to identify parallelizable texts for Church Slavic, across chronological and regional variants. Next to using a benchmark text, we utilize a recently digitized, large text collection and compile new resources for the retrieval of similar texts: a ground truth dataset holding a small amount of manually aligned sentences in Old Church Slavic and in Old East Slavic, and a large unaligned dataset that has a subset of ground truth (GT) quality texts but contains noise from handwritten text recognition (HTR) for the majority of the collection. We discuss preprocessing challenges in the data and the impact of sentence segmentation on retrieval performance. We evaluate sentence snippets mapped across these two diachronic variants of Church Slavic, expressed by mean reciprocal rank, using embedding representations from large language models (LLMs) as well as classical string similarity based approaches combined with k-nearest neighbor (kNN) search. Experimental results indicate that in the current setup (short text snippets, off-the-shelf multilingual embeddings), classical string similarity based retrieval can still outperform embedding based retrieval.

We describe ongoing work for developing a workflow for the applied use case of classifying diachronic and regional language variation in Pre-Modern Slavic texts. The data were obtained via handwritten text recognition (HTR) on medieval manuscripts and printings and partly by manual transcription. Our goal is to develop a workflow for such historical language data, covering HTR-postprocessing, annotating and classifying the digitized texts. We test and adapt existing language resources to fit the pipeline with low-barrier tooling, accessible for Humanists with limited experience in research data infrastructures, computational analysis or advanced methods of natural language processing (NLP). The workflow starts by addressing ground truth (GT) data creation for diagnosing and correcting HTR errors via string metrics and data-driven methods. On GT and on HTR data, we subsequently show classification results using transfer learning on sentence-level text snippets. Next, we report on our token-level data labeling efforts. Each step of the workflow is complemented with describing current limitations and our corresponding work in progress.

Our study presents a stratified dataset compiled from six different Slavic bodies of text, for cross-linguistic and diachronic analyses of Slavic Pre-Modern language variants. We demonstrate unsupervised domain adaptation and supervised finetuning of BERT on these low-resource, historical Slavic variants, for the purposes of provenance attribution in terms of three downstream tasks: manuscript, century and copying region classification.The data compilation aims to capture diachronic as well as regional language variation and change: the texts were written in the course of roughly a millennium, incorporating language variants from the High Middle Ages to the Early Modern Period, and originate from a variety of geographic regions. Mechanisms of language change in relatively small portions of such data have been inspected, analyzed and typologized by Slavists manually; our contribution aims to investigate the extent to which the BERT transformer architecture and pretrained models can benefit this process. Using these datasets for domain adaptation, we could attribute temporal, geographical and manuscript origin on the level of text snippets with high F-scores. We also conducted a qualitative analysis of the models’ misclassifications.