This paper addresses the problem of word sense induction (WSI) via clustering of word embeddings. It starts from the hypothesis that contextualized word representations obtained from pre-trained language models (LMs), while being a valuable source for WSI, encode more information than what is necessary for the identification of word senses and some of this information affect the performance negatively in unsupervised settings. We investigate whether using contextualized representations that are invariant to these ‘nuisance features’ can increase WSI performance. For this purpose, we propose an adaptation of the adversarial training framework proposed by Jaiswal et al. (2020) to erase specific information from the representations of LMs, thereby creating feature-invariant representations. We experiment with erasing (i) morphological and (ii) syntactic features. The results of subsequent clustering for WSI show that these features indeed act like noise: Using feature-invariant representations, compared to using the original representations, increases clustering-based WSI performance. Furthermore, we provide an in-depth analysis of how the information about the syntactic and morphological features of words relate to and affect WSI performance.

The similarity of representations is crucial for WSD. However, a lot of information is encoded in the contextualized representations, and it is not clear which sentence context features drive this similarity and whether these features are significant to WSD. In this study, we address these questions. First, we identify the sentence context features that are responsible for the similarity of the contextualized representations of different occurrences of words. For this purpose, we conduct an explainability experiment and identify the sentence context features that lead to the formation of the clusters in word sense clustering with CWEs. Then, we provide a qualitative evaluation for assessing the significance of these features to WSD. Our results show that features that lack significance to WSD determine the similarity of the representations even when different senses of a word occur in highly diverse contexts and sentence context provides clear clues for different senses.

Identifying semantic argument types in predication contexts is not a straightforward task for several reasons, such as inherent polysemy, coercion, and copredication phenomena. In this paper, we train monolingual and multilingual classifiers with a zero-shot cross-lingual approach to identify semantic argument types in predications using pre-trained language models as feature extractors. We train classifiers for different semantic argument types and for both verbal and adjectival predications. Furthermore, we propose a method to detect copredication using these classifiers through identifying the argument semantic type targeted in different predications over the same noun in a sentence. We evaluate the performance of the method on copredication test data with Food•Event nouns for 5 languages.