Elizabeth Nielsen


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Spelling convention sensitivity in neural language models
Elizabeth Nielsen | Christo Kirov | Brian Roark
Findings of the Association for Computational Linguistics: EACL 2023

We examine whether large neural language models, trained on very large collections of varied English text, learn the potentially long-distance dependency of British versus American spelling conventions, i.e., whether spelling is consistently one or the other within model-generated strings. In contrast to long-distance dependencies in non-surface underlying structure (e.g., syntax), spelling consistency is easier to measure both in LMs and the text corpora used to train them, which can provide additional insight into certain observed model behaviors. Using a set of probe words unique to either British or American English, we first establish that training corpora exhibit substantial (though not total) consistency. A large T5 language model does appear to internalize this consistency, though only with respect to observed lexical items (not nonce words with British/American spelling patterns). We further experiment with correcting for biases in the training data by fine-tuning T5 on synthetic data that has been debiased, and find that finetuned T5 remains only somewhat sensitive to spelling consistency. Further experiments show GPT2 to be similarly limited.

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Distinguishing Romanized Hindi from Romanized Urdu
Elizabeth Nielsen | Christo Kirov | Brian Roark
Proceedings of the Workshop on Computation and Written Language (CAWL 2023)

We examine the task of distinguishing between Hindi and Urdu when those languages are romanized, i.e., written in the Latin script. Both languages are widely informally romanized, and to the extent that they are identified in the Latin script by language identification systems, they are typically conflated. In the absence of large labeled collections of such text, we consider methods for generating training data. Beginning with a small set of seed words, each of which are strongly indicative of one of the languages versus the other, we prompt a pretrained large language model (LLM) to generate romanized text. Treating text generated from an Urdu prompt as one class and text generated from a Hindi prompt as the other class, we build a binary language identification (LangID) classifier. We demonstrate that the resulting classifier distinguishes manually romanized Urdu Wikipedia text from manually romanized Hindi Wikipedia text far better than chance. We use this classifier to estimate the prevalence of Urdu in a large collection of text labeled as romanized Hindi that has been used to train large language models. These techniques can be applied to bootstrap classifiers in other cases where a dataset is known to contain multiple distinct but related classes, such as different dialects of the same language, but for which labels cannot easily be obtained.


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Zero-shot Cross-Linguistic Learning of Event Semantics
Malihe Alikhani | Thomas Kober | Bashar Alhafni | Yue Chen | Mert Inan | Elizabeth Nielsen | Shahab Raji | Mark Steedman | Matthew Stone
Proceedings of the 15th International Conference on Natural Language Generation


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The role of context in neural pitch accent detection in English
Elizabeth Nielsen | Mark Steedman | Sharon Goldwater
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

Prosody is a rich information source in natural language, serving as a marker for phenomena such as contrast. In order to make this information available to downstream tasks, we need a way to detect prosodic events in speech. We propose a new model for pitch accent detection, inspired by the work of Stehwien et al. (2018), who presented a CNN-based model for this task. Our model makes greater use of context by using full utterances as input and adding an LSTM layer. We find that these innovations lead to an improvement from 87.5% to 88.7% accuracy on pitch accent detection on American English speech in the Boston University Radio News Corpus, a state-of-the-art result. We also find that a simple baseline that just predicts a pitch accent on every content word yields 82.2% accuracy, and we suggest that this is the appropriate baseline for this task. Finally, we conduct ablation tests that show pitch is the most important acoustic feature for this task and this corpus.