ymoslem/acl-abstracts huggingface dataset:
Forming Trees with Treeformers (2023)

Human language is known to exhibit a nested, hierarchical structure, allowing us to form complex sentences out of smaller pieces. However, many state-of-the-art neural networks models such as Transformers have no explicit hierarchical structure in their architecture{---}that is, they don`t have an inductive bias toward hierarchical structure. Additionally, Transformers are known to perform poorly on compositional generalization tasks which require such structures. In this paper, we introduce Treeformer, a general-purpose encoder module inspired by the CKY algorithm which learns a composition operator and pooling function to construct hierarchical encodings for phrases and sentences. Our extensive experiments demonstrate the benefits of incorporating hierarchical structure into the Transformer and show significant improvements in compositional generalization as well as in downstream tasks such as machine translation, abstractive summarization, and various natural language understanding tasks.
Evaluating Unsupervised Hierarchical Topic Models Using a Labeled Dataset (2023)

Topic modeling is a commonly used method for identifying and extracting topics from a corpus of documents. While several evaluation techniques, such as perplexity and topic coherence, have been developed to assess the quality of extracted topics, they fail to determine whether all topics have been identified and to what extent they have been represented. Additionally, hierarchical topic models have been proposed, but the quality of the hierarchy produced has not been adequately evaluated. This study proposes a novel approach to evaluating topic models that supplements existing methods. Using a labeled dataset, we trained hierarchical topic models in an unsupervised manner and used the known labels to evaluate the accuracy of the results. Our findings indicate that labels encompassing a substantial number of documents achieve high accuracy of over 70{\%}. Although there are 90 labels in the dataset, labels that cover only 1{\%} of the data still achieve an average accuracy of 37.9{\%}, demonstrating the effectiveness of hierarchical topic models even on smaller subsets. Furthermore, we demonstrate that these labels can be used to assess the quality of the topic tree and confirm that hierarchical topic models produce coherent taxonomies for the labels.
HTMOT: Hierarchical Topic Modelling over Time (2023)

Topic models provide an efficient way of extracting insights from text and supporting decision-making. Recently, novel methods have been proposed to model topic hierarchy or temporality. Modeling temporality provides more precise topics by separating topics that are characterized by similar words but located over distinct time periods. Conversely, modeling hierarchy provides a more detailed view of the content of a corpus by providing topics and sub-topics. However, no models have been proposed to incorporate both hierarchy and temporality which could be beneficial for applications such as environment scanning. Therefore, we propose a novel method to perform Hierarchical Topic Modelling Over Time (HTMOT). We evaluate the performance of our approach on a corpus of news articles using the Word Intrusion task. Results demonstrate that our model produces topics that elegantly combine a hierarchical structure and a temporal aspect. Furthermore, our proposed Gibbs sampling implementation shows competitive performance compared to previous state-of-the-art methods.
Multilingual Continual Learning Approaches for Text Classification (2023)

Multilingual continual learning is important for models that are designed to be deployed over long periods of time and are required to be updated when new data becomes available. Such models are continually applied to new unseen data that can be in any of the supported languages. One challenge in this scenario is to ensure consistent performance of the model throughout the deployment lifecycle, beginning from the moment of first deployment. We empirically assess the strengths and shortcomings of some continual learning methods in a multilingual setting across two tasks.
Can Model Fusing Help Transformers in Long Document Classification? An Empirical Study (2023)

Text classification is an area of research which has been studied over the years in Natural Language Processing (NLP). Adapting NLP to multiple domains has introduced many new challenges for text classification and one of them is long document classification. While state-of-the-art transformer models provide excellent results in text classification, most of them have limitations in the maximum sequence length of the input sequence. The majority of the transformer models are limited to 512 tokens, and therefore, they struggle with long document classification problems. In this research, we explore on employing Model Fusing for long document classification while comparing the results with well-known BERT and Longformer architectures.
Deep Learning Methods for Identification of Multiword Flower and Plant Names (2023)

Multiword Terms (MWTs) are domain-specific Multiword Expressions (MWE) where two or more lexemes converge to form a new unit of meaning. The task of processing MWTs is crucial in many Natural Language Processing (NLP) applications, including Machine Translation (MT) and terminology extraction. However, the automatic detection of those terms is a difficult task and more research is still required to give more insightful and useful results in this field. In this study, we seek to fill this gap using state-of-the-art transformer models. We evaluate both BERT like discriminative transformer models and generative pre-trained transformer (GPT) models on this task, and we show that discriminative models perform better than current GPT models in multi-word terms identification task in flower and plant names in English and Spanish languages. Best discriminate models perform 94.3127{\%}, 82.1733{\%} F1 scores in English and Spanish data, respectively while ChatGPT could only perform 63.3183{\%} and 47.7925{\%} respectively.
Improving Aspect-Based Sentiment with End-to-End Semantic Role Labeling Model (2023)

This paper presents a series of approaches aimed at enhancing the performance of Aspect-Based Sentiment Analysis (ABSA) by utilizing extracted semantic information from a Semantic Role Labeling (SRL) model. We propose a novel end-to-end Semantic Role Labeling model that effectively captures most of the structured semantic information within the Transformer hidden state. We believe that this end-to-end model is well-suited for our newly proposed models that incorporate semantic information. We evaluate the proposed models in two languages, English and Czech, employing ELECTRA-small models. Our combined models improve ABSA performance in both languages. Moreover, we achieved new state-of-the-art results on the Czech ABSA.
huPWKP: A Hungarian Text Simplification Corpus (2023)

In this article we introduce huPWKP, the first parallel corpus consisting of Hungarian standard language-simplified sentence pairs. As Hungarian is a quite low-resource language in regards to text simplification, we opted for translating an already existing corpus, PWKP (Zhu et al., 2010), on which we performed some cleaning in order to improve its quality. We evaluated the corpus both with the help of human evaluators and by training a seq2seq model on both the Hungarian corpus and the original (cleaned) English corpus. The Hungarian model performed slightly worse in terms of automatic metrics; however, the English model attains a SARI score close to the state of the art on the official PWKP set. According to the human evaluation, the corpus performs at around 3 on a scale ranging from 1 to 5 in terms of information retention and increase in simplification and around 3.7 in terms of grammaticality.
Topic Modeling Using Community Detection on a Word Association Graph (2023)

Topic modeling of a text corpus is one of the most well-studied areas of information retrieval and knowledge discovery. Despite several decades of research in the area that begets an array of modeling tools, some common problems still obstruct automated topic modeling from matching users' expectations. In particular, existing topic modeling solutions suffer when the distribution of words among the underlying topics is uneven or the topics are overlapped. Furthermore, many solutions ask the user to provide a topic count estimate as input, which limits their usefulness in modeling a corpus where such information is unavailable. We propose a new topic modeling approach that overcomes these shortcomings by formulating the topic modeling problem as a community detection problem in a word association graph/network that we generate from the text corpus. Experimental evaluation using multiple data sets of three different types of text corpora shows that our approach is superior to prominent topic modeling alternatives in most cases. This paper describes our approach and discusses the experimental findings.
Exploring Techniques to Detect and Mitigate Non-Inclusive Language Bias in Marketing Communications Using a Dictionary-Based Approach (2023)

We propose a new dataset for detecting non-inclusive language in sentences in English. These sentences were gathered from public sites, explaining what is inclusive and what is non-inclusive. We also extracted potentially non-inclusive keywords/phrases from the guidelines from business websites. A phrase dictionary was created by using an automatic extension with a word embedding trained on a massive corpus of general English text. In the end, a phrase dictionary was constructed by hand-editing the previous one to exclude inappropriate expansions and add the keywords from the guidelines. In a business context, the words individuals use can significantly impact the culture of inclusion and the quality of interactions with clients and prospects. Knowing the right words to avoid helps customers of different backgrounds and historically excluded groups feel included. They can make it easier to have productive, engaging, and positive communications. You can find the dictionaries, the code, and the method for making requests for the corpus at (we will release the link for data and code once the paper is accepted).
Does the \textquotedblleftMost Sinfully Decadent Cake Ever\textquotedblright Taste Good? Answering Yes/No Questions from Figurative Contexts (2023)

Figurative language is commonplace in natural language, and while making communication memorable and creative, can be difficult to understand. In this work, we investigate the robustness of Question Answering (QA) models on figurative text. Yes/no questions, in particular, are a useful probe of figurative language understanding capabilities of large language models. We propose FigurativeQA, a set of 1000 yes/no questions with figurative and non-figurative contexts, extracted from the domains of restaurant and product reviews. We show that state-of-the-art BERT-based QA models exhibit an average performance drop of up to 15{\%} points when answering questions from figurative contexts, as compared to non-figurative ones. While models like GPT-3 and ChatGPT are better at handling figurative texts, we show that further performance gains can be achieved by automatically simplifying the figurative contexts into their non-figurative (literal) counterparts. We find that the best overall model is ChatGPT with chain-of-thought prompting to generate non-figurative contexts. Our work provides a promising direction for building more robust QA models with figurative language understanding capabilities.
Modeling Easiness for Training Transformers with Curriculum Learning (2023)

Directly learning from complex examples is generally problematic for humans and machines. Indeed, a better strategy is exposing learners to examples in a reasonable, pedagogically-motivated order. Curriculum Learning (CL) has been proposed to import this strategy when training machine learning models. In this paper, building on Curriculum Learning, we propose a novel, linguistically motivated measure to determine example complexity for organizing examples during learning. Our complexity measure - LRC- is based on length, rarity, and comprehensibility. Our resulting learning model is CL-LRC, that is, CL with LRC. Experiments on downstream tasks show that CL-LRC outperforms existing CL and non-CL methods for training BERT and RoBERTa from scratch. Furthermore, we analyzed different measures, including perplexity, loss, and learning curve of different models pre-trained from scratch, showing that CL-LRC performs better than the state-of-the-art.
The Dark Side of the Language: Pre-trained Transformers in the DarkNet (2023)

Pre-trained Transformers are challenging human performances in many Natural Language Processing tasks. The massive datasets used for pre-training seem to be the key to their success on existing tasks. In this paper, we explore how a range of pre-trained natural language understanding models performs on definitely unseen sentences provided by classification tasks over a DarkNet corpus. Surprisingly, results show that syntactic and lexical neural networks perform on par with pre-trained Transformers even after fine-tuning. Only after what we call extreme domain adaptation, that is, retraining with the masked language model task on all the novel corpus, pre-trained Transformers reach their standard high results. This suggests that huge pre-training corpora may give Transformers unexpected help since they are exposed to many of the possible sentences.
PreCog: Exploring the Relation between Memorization and Performance in Pre-trained Language Models (2023)

Large Language Models (LLMs) are impressive machines with the ability to memorize, possibly generalized learning examples. We present here a small, focused contribution to the analysis of the interplay between memorization and performance of BERT in downstream tasks. We propose PreCog, a measure for evaluating memorization from pre-training, and we analyze its correlation with the BERT`s performance. Our experiments show that highly memorized examples are better classified, suggesting memorization is an essential key to success for BERT.
Publish or Hold? Automatic Comment Moderation in Luxembourgish News Articles (2023)

Recently, the internet has emerged as the primary platform for accessing news. In the majority of these news platforms, the users now have the ability to post comments on news articles and engage in discussions on various social media. While these features promote healthy conversations among users, they also serve as a breeding ground for spreading fake news, toxic discussions and hate speech. Moderating or removing such content is paramount to avoid unwanted consequences for the readers. How- ever, apart from a few notable exceptions, most research on automatic moderation of news article comments has dealt with English and other high resource languages. This leaves under-represented or low-resource languages at a loss. Addressing this gap, we perform the first large-scale qualitative analysis of more than one million Luxembourgish comments posted over the course of 14 years. We evaluate the performance of state-of-the-art transformer models in Luxembourgish news article comment moderation. Furthermore, we analyse how the language of Luxembourgish news article comments has changed over time. We observe that machine learning models trained on old comments do not perform well on recent data. The findings in this work will be beneficial in building news comment moderation systems for many low-resource languages
Cross-Lingual Speaker Identification for Indian Languages (2023)

The paper introduces a cross-lingual speaker identification system for Indian languages, utilising a Long Short-Term Memory dense neural network (LSTM-DNN). The system was trained on audio recordings in English and evaluated on data from Hindi, Kannada, Malayalam, Tamil, and Telugu, with a view to how factors such as phonetic similarity and native accent affect performance. The model was fed with MFCC (mel-frequency cepstral coefficient) features extracted from the audio file. For comparison, the corresponding mel-spectrogram images were also used as input to a ResNet-50 model, while the raw audio was used to train a Siamese network. The LSTM-DNN model outperformed the other two models as well as two more traditional baseline speaker identification models, showing that deep learning models are superior to probabilistic models for capturing low-level speech features and learning speaker characteristics.
\textquoteleftChemXtract' A System for Extraction of Chemical Events from Patent Documents (2023)

ChemXtraxt main goal is to extract the chemical events from patent documents. Event extraction requires that we first identify the names of chemical compounds involved in the events. Thus, in this work two extractions are done and they are (a) names of chemical compounds and (b) event that identify the specific involvement of the chemical compounds in a chemical reaction. Extraction of essential elements of a chemical reaction, generally known as Named Entity Recognition (NER), extracts the compounds, condition and yields, their specific role in reaction and assigns a label according to the role it plays within a chemical reaction. Whereas event extraction identifies the chemical event relations between the chemical compounds identified. Here in this work we have used Neural Conditional Random Fields (NCRF), which combines the power of artificial neural network (ANN) and CRFs. Different levels of features that include linguistic, orthographical and lexical clues are used. The results obtained are encouraging.
Mind the User! Measures to More Accurately Evaluate the Practical Value of Active Learning Strategies (2023)

One solution to limited annotation budgets is active learning (AL), a collaborative process of human and machine to strategically select a small but informative set of examples. While current measures optimize AL from a pure machine learning perspective, we argue that for a successful transfer into practice, additional criteria must target the second pillar of AL, the human annotator. In text classification, e.g., where practitioners regularly encounter datasets with an increased number of imbalanced classes, measures like F1 fall short when finding all classes or identifying rare cases is required. We therefore introduce four measures that reflect class-related demands that users place on data acquisition. In a comprehensive comparison of uncertainty-based, diversity-based, and hybrid query strategies on six different datasets, we find that strong F1 performance is not necessarily associated with full class coverage. Uncertainty sampling outperforms diversity sampling in selecting minority classes and covering classes more efficiently, while diversity sampling excels in selecting less monotonous batches. Our empirical findings emphasize that a holistic view is essential when evaluating AL approaches to ensure their usefulness in practice - the actual, but often overlooked, goal of development. To this end, standard measures for assessing the performance of text classification need to be complemented by such that more appropriately reflect user needs.
Event Annotation and Detection in Kannada-English Code-Mixed Social Media Data (2023)

Code-mixing (CM) is a frequently observed phenomenon on social media platforms in multilingual societies such as India. While the increase in code-mixed content on these platforms provides good amount of data for studying various aspects of code-mixing, the lack of automated text analysis tools makes such studies difficult. To overcome the same, tools such as language identifiers, Parts-of-Speech (POS) taggers and Named Entity Recognition (NER) for analysing code-mixed data have been developed. One such important tool is Event Detection, an important information retrieval task which can be used to identify critical facts occurring in the vast streams of unstructured text data available. While event detection from text is a hard problem on its own, social media data adds to it with its informal nature, and code-mixed (Kannada-English) data further complicates the problem due to its word-level mixing, lack of structure and incomplete information. In this work, we have tried to address this problem. We have proposed guidelines for the annotation of events in Kannada-English CM data and provided some baselines for the same with careful feature selection.
Three Approaches to Client Email Topic Classification (2023)

This paper describes a use case that was implemented and is currently running in production at the Nova Ljubljanska Banka, that involves classifying incoming client emails in the Slovenian language according to their topics and priorities. Since the proposed approach relies only on the Named Entity Recogniser (NER) of personal names as a language-dependent resource (for the purpose of anonymisation), that is the only prerequisite for applying the approach to any other language.
Exploring Abstractive Text Summarisation for Podcasts: A Comparative Study of BART and T5 Models (2023)

Podcasts have become increasingly popular in recent years, resulting in a massive amount of audio content being produced every day. Efficient summarisation of podcast episodes can enable better content management and discovery for users. In this paper, we explore the use of abstractive text summarisation methods to generate high-quality summaries of podcast episodes. We use pre-trained models, BART and T5, to fine-tune on a dataset of Spotify`s 100K podcast. We evaluate our models using automated metrics and human evaluation, and find that the BART model fine-tuned on the podcast dataset achieved a higher ROUGE-1 and ROUGE-L score compared to other models, while the T5 model performed better in terms of semantic meaning. The human evaluation indicates that both models produced high-quality summaries that were well received by participants. Our study demonstrates the effectiveness of abstractive summarisation methods for podcast episodes and offers insights for improving the summarisation of audio content.
Exploring the Landscape of Natural Language Processing Research (2023)

As an efficient approach to understand, generate, and process natural language texts, research in natural language processing (NLP) has exhibited a rapid spread and wide adoption in recent years. Given the increasing research work in this area, several NLP-related approaches have been surveyed in the research community. However, a comprehensive study that categorizes established topics, identifies trends, and outlines areas for future research remains absent. Contributing to closing this gap, we have systematically classified and analyzed research papers in the ACL Anthology. As a result, we present a structured overview of the research landscape, provide a taxonomy of fields of study in NLP, analyze recent developments in NLP, summarize our findings, and highlight directions for future work.