Interpretability studies have played an important role in the field of NLP. They focus on the problems of how models encode information or, for instance, whether linguistic capabilities allow them to prefer grammatical sentences to ungrammatical. Recently, several studies examined whether the models demonstrate patterns similar to humans and whether they are sensitive to the phenomena of interference like humans’ grammaticality judgements, including the phenomenon of agreement attraction.In this paper, we probe BERT and GPT models on the syntactic phenomenon of agreement attraction in Russian using the psycholinguistic data with syncretism. Working on the language with syncretism between some plural and singular forms allows us to differentiate between the effects of the surface form and of the underlying grammatical feature. Thus we can further investigate models’ sensitivity to this phenomenon and examine if the patterns of their behaviour are similar to human patterns. Moreover, we suggest a new way of comparing models’ and humans’ responses via statistical testing. We show that there are some similarities between models’ and humans’ results, while GPT is somewhat more aligned with human responses than BERT. Finally, preliminary results suggest that surface form syncretism influences attraction, perhaps more so than grammatical form syncretism.

A broad goal in natural language processing (NLP) is to develop a system that has the capacity to process any natural language. Most systems, however, are developed using data from just one language such as English. The SIGMORPHON 2020 shared task on morphological reinflection aims to investigate systems’ ability to generalize across typologically distinct languages, many of which are low resource. Systems were developed using data from 45 languages and just 5 language families, fine-tuned with data from an additional 45 languages and 10 language families (13 in total), and evaluated on all 90 languages. A total of 22 systems (19 neural) from 10 teams were submitted to the task. All four winning systems were neural (two monolingual transformers and two massively multilingual RNN-based models with gated attention). Most teams demonstrate utility of data hallucination and augmentation, ensembles, and multilingual training for low-resource languages. Non-neural learners and manually designed grammars showed competitive and even superior performance on some languages (such as Ingrian, Tajik, Tagalog, Zarma, Lingala), especially with very limited data. Some language families (Afro-Asiatic, Niger-Congo, Turkic) were relatively easy for most systems and achieved over 90% mean accuracy while others were more challenging.

Results of the first experimental evaluation of machine learning models trained on Ru-RSTreebank – first Russian corpus annotated within RST framework – are presented. Various lexical, quantitative, morphological, and semantic features were used. In rhetorical relation classification, ensemble of CatBoost model with selected features and a linear SVM model provides the best score (macro F1 = 54.67 ± 0.38). We discover that most of the important features for rhetorical relation classification are related to discourse connectives derived from the connectives lexicon for Russian and from other sources.