Le An Ha


2020

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Verbal Multiword Expressions for Identification of Metaphor
Omid Rohanian | Marek Rei | Shiva Taslimipoor | Le An Ha
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics

Metaphor is a linguistic device in which a concept is expressed by mentioning another. Identifying metaphorical expressions, therefore, requires a non-compositional understanding of semantics. Multiword Expressions (MWEs), on the other hand, are linguistic phenomena with varying degrees of semantic opacity and their identification poses a challenge to computational models. This work is the first attempt at analysing the interplay of metaphor and MWEs processing through the design of a neural architecture whereby classification of metaphors is enhanced by informing the model of the presence of MWEs. To the best of our knowledge, this is the first “MWE-aware” metaphor identification system paving the way for further experiments on the complex interactions of these phenomena. The results and analyses show that this proposed architecture reach state-of-the-art on two different established metaphor datasets.

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A First Dataset for Film Age Appropriateness Investigation
Emad Mohamed | Le An Ha
Proceedings of the 12th Language Resources and Evaluation Conference

Film age appropriateness classification is an important problem with a significant societal impact that has so far been out of the interest of Natural Language Processing and Machine Learning researchers. To this end, we have collected a corpus of 17000 films along with their age ratings. We use the textual contents in an experiment to predict the correct age classification for the United States (G, PG, PG-13, R and NC-17) and the United Kingdom (U, PG, 12A, 15, 18 and R18). Our experiments indicate that gradient boosting machines beat FastText and various Deep Learning architectures. We reach an overall accuracy of 79.3% for the US ratings compared to a projected super human accuracy of 84%. For the UK ratings, we reach an overall accuracy of 65.3% (UK) compared to a projected super human accuracy of 80.0%.

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Predicting Item Survival for Multiple Choice Questions in a High-Stakes Medical Exam
Victoria Yaneva | Le An Ha | Peter Baldwin | Janet Mee
Proceedings of the 12th Language Resources and Evaluation Conference

One of the most resource-intensive problems in the educational testing industry relates to ensuring that newly-developed exam questions can adequately distinguish between students of high and low ability. The current practice for obtaining this information is the costly procedure of pretesting: new items are administered to test-takers and then the items that are too easy or too difficult are discarded. This paper presents the first study towards automatic prediction of an item’s probability to “survive” pretesting (item survival), focusing on human-produced MCQs for a medical exam. Survival is modeled through a number of linguistic features and embedding types, as well as features inspired by information retrieval. The approach shows promising first results for this challenging new application and for modeling the difficulty of expert-knowledge questions.

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Automated Prediction of Examinee Proficiency from Short-Answer Questions
Le An Ha | Victoria Yaneva | Polina Harik | Ravi Pandian | Amy Morales | Brian Clauser
Proceedings of the 28th International Conference on Computational Linguistics

This paper brings together approaches from the fields of NLP and psychometric measurement to address the problem of predicting examinee proficiency from responses to short-answer questions (SAQs). While previous approaches train on manually labeled data to predict the human-ratings assigned to SAQ responses, the approach presented here models examinee proficiency directly and does not require manually labeled data to train on. We use data from a large medical exam where experimental SAQ items are embedded alongside 106 scored multiple-choice questions (MCQs). First, the latent trait of examinee proficiency is measured using the scored MCQs and then a model is trained on the experimental SAQ responses as input, aiming to predict proficiency as its target variable. The predicted value is then used as a “score” for the SAQ response and evaluated in terms of its contribution to the precision of proficiency estimation.

2019

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Predicting the Difficulty of Multiple Choice Questions in a High-stakes Medical Exam
Le An Ha | Victoria Yaneva | Peter Baldwin | Janet Mee
Proceedings of the Fourteenth Workshop on Innovative Use of NLP for Building Educational Applications

Predicting the construct-relevant difficulty of Multiple-Choice Questions (MCQs) has the potential to reduce cost while maintaining the quality of high-stakes exams. In this paper, we propose a method for estimating the difficulty of MCQs from a high-stakes medical exam, where all questions were deliberately written to a common reading level. To accomplish this, we extract a large number of linguistic features and embedding types, as well as features quantifying the difficulty of the items for an automatic question-answering system. The results show that the proposed approach outperforms various baselines with a statistically significant difference. Best results were achieved when using the full feature set, where embeddings had the highest predictive power, followed by linguistic features. An ablation study of the various types of linguistic features suggested that information from all levels of linguistic processing contributes to predicting item difficulty, with features related to semantic ambiguity and the psycholinguistic properties of words having a slightly higher importance. Owing to its generic nature, the presented approach has the potential to generalize over other exams containing MCQs.

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Cross-lingual Transfer Learning and Multitask Learning for Capturing Multiword Expressions
Shiva Taslimipoor | Omid Rohanian | Le An Ha
Proceedings of the Joint Workshop on Multiword Expressions and WordNet (MWE-WN 2019)

Recent developments in deep learning have prompted a surge of interest in the application of multitask and transfer learning to NLP problems. In this study, we explore for the first time, the application of transfer learning (TRL) and multitask learning (MTL) to the identification of Multiword Expressions (MWEs). For MTL, we exploit the shared syntactic information between MWE and dependency parsing models to jointly train a single model on both tasks. We specifically predict two types of labels: MWE and dependency parse. Our neural MTL architecture utilises the supervision of dependency parsing in lower layers and predicts MWE tags in upper layers. In the TRL scenario, we overcome the scarcity of data by learning a model on a larger MWE dataset and transferring the knowledge to a resource-poor setting in another language. In both scenarios, the resulting models achieved higher performance compared to standard neural approaches.

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Automatic Question Answering for Medical MCQs: Can It go Further than Information Retrieval?
Le An Ha | Victoria Yaneva
Proceedings of the International Conference on Recent Advances in Natural Language Processing (RANLP 2019)

We present a novel approach to automatic question answering that does not depend on the performance of an information retrieval (IR) system and does not require that the training data come from the same source as the questions. We evaluate the system performance on a challenging set of university-level medical science multiple-choice questions. Best performance is achieved when combining a neural approach with an IR approach, both of which work independently. Unlike previous approaches, the system achieves statistically significant improvement over the random guess baseline even for questions that are labeled as challenging based on the performance of baseline solvers.

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A Survey of the Perceived Text Adaptation Needs of Adults with Autism
Victoria Yaneva | Constantin Orasan | Le An Ha | Natalia Ponomareva
Proceedings of the International Conference on Recent Advances in Natural Language Processing (RANLP 2019)

NLP approaches to automatic text adaptation often rely on user-need guidelines which are generic and do not account for the differences between various types of target groups. One such group are adults with high-functioning autism, who are usually able to read long sentences and comprehend difficult words but whose comprehension may be impeded by other linguistic constructions. This is especially challenging for real-world user-generated texts such as product reviews, which cannot be controlled editorially and are thus a particularly good applcation for automatic text adaptation systems. In this paper we present a mixed-methods survey conducted with 24 adult web-users diagnosed with autism and an age-matched control group of 33 neurotypical participants. The aim of the survey was to identify whether the group with autism experienced any barriers when reading online reviews, what these potential barriers were, and what NLP methods would be best suited to improve the accessibility of online reviews for people with autism. The group with autism consistently reported significantly greater difficulties with understanding online product reviews compared to the control group and identified issues related to text length, poor topic organisation, and the use of irony and sarcasm.

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Bridging the Gap: Attending to Discontinuity in Identification of Multiword Expressions
Omid Rohanian | Shiva Taslimipoor | Samaneh Kouchaki | Le An Ha | Ruslan Mitkov
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)

We introduce a new method to tag Multiword Expressions (MWEs) using a linguistically interpretable language-independent deep learning architecture. We specifically target discontinuity, an under-explored aspect that poses a significant challenge to computational treatment of MWEs. Two neural architectures are explored: Graph Convolutional Network (GCN) and multi-head self-attention. GCN leverages dependency parse information, and self-attention attends to long-range relations. We finally propose a combined model that integrates complementary information from both, through a gating mechanism. The experiments on a standard multilingual dataset for verbal MWEs show that our model outperforms the baselines not only in the case of discontinuous MWEs but also in overall F-score.

2018

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Wolves at SemEval-2018 Task 10: Semantic Discrimination based on Knowledge and Association
Shiva Taslimipoor | Omid Rohanian | Le An Ha | Gloria Corpas Pastor | Ruslan Mitkov
Proceedings of The 12th International Workshop on Semantic Evaluation

This paper describes the system submitted to SemEval 2018 shared task 10 ‘Capturing Dicriminative Attributes’. We use a combination of knowledge-based and co-occurrence features to capture the semantic difference between two words in relation to an attribute. We define scores based on association measures, ngram counts, word similarity, and ConceptNet relations. The system is ranked 4th (joint) on the official leaderboard of the task.

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Classifying Referential and Non-referential It Using Gaze
Victoria Yaneva | Le An Ha | Richard Evans | Ruslan Mitkov
Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing

When processing a text, humans and machines must disambiguate between different uses of the pronoun it, including non-referential, nominal anaphoric or clause anaphoric ones. In this paper we use eye-tracking data to learn how humans perform this disambiguation and use this knowledge to improve the automatic classification of it. We show that by using gaze data and a POS-tagger we are able to significantly outperform a common baseline and classify between three categories of it with an accuracy comparable to that of linguistic-based approaches. In addition, the discriminatory power of specific gaze features informs the way humans process the pronoun, which, to the best of our knowledge, has not been explored using data from a natural reading task.

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Automatic Distractor Suggestion for Multiple-Choice Tests Using Concept Embeddings and Information Retrieval
Le An Ha | Victoria Yaneva
Proceedings of the Thirteenth Workshop on Innovative Use of NLP for Building Educational Applications

Developing plausible distractors (wrong answer options) when writing multiple-choice questions has been described as one of the most challenging and time-consuming parts of the item-writing process. In this paper we propose a fully automatic method for generating distractor suggestions for multiple-choice questions used in high-stakes medical exams. The system uses a question stem and the correct answer as an input and produces a list of suggested distractors ranked based on their similarity to the stem and the correct answer. To do this we use a novel approach of combining concept embeddings with information retrieval methods. We frame the evaluation as a prediction task where we aim to “predict” the human-produced distractors used in large sets of medical questions, i.e. if a distractor generated by our system is good enough it is likely to feature among the list of distractors produced by the human item-writers. The results reveal that combining concept embeddings with information retrieval approaches significantly improves the generation of plausible distractors and enables us to match around 1 in 5 of the human-produced distractors. The approach proposed in this paper is generalisable to all scenarios where the distractors refer to concepts.

2017

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Using Gaze Data to Predict Multiword Expressions
Omid Rohanian | Shiva Taslimipoor | Victoria Yaneva | Le An Ha
Proceedings of the International Conference Recent Advances in Natural Language Processing, RANLP 2017

In recent years gaze data has been increasingly used to improve and evaluate NLP models due to the fact that it carries information about the cognitive processing of linguistic phenomena. In this paper we conduct a preliminary study towards the automatic identification of multiword expressions based on gaze features from native and non-native speakers of English. We report comparisons between a part-of-speech (POS) and frequency baseline to: i) a prediction model based solely on gaze data and ii) a combined model of gaze data, POS and frequency. In spite of the challenging nature of the task, best performance was achieved by the latter. Furthermore, we explore how the type of gaze data (from native versus non-native speakers) affects the prediction, showing that data from the two groups is discriminative to an equal degree for the task. Finally, we show that late processing measures are more predictive than early ones, which is in line with previous research on idioms and other formulaic structures.

2012

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Automatic Question Generation in Multimedia-Based Learning
Yvonne Skalban | Le An Ha | Lucia Specia | Ruslan Mitkov
Proceedings of COLING 2012: Posters

2009

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Semantic Similarity of Distractors in Multiple-Choice Tests: Extrinsic Evaluation
Ruslan Mitkov | Le An Ha | Andrea Varga | Luz Rello
Proceedings of the Workshop on Geometrical Models of Natural Language Semantics

2008

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Mutual Bilingual Terminology Extraction
Le An Ha | Gabriela Fernandez | Ruslan Mitkov | Gloria Corpas
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

This paper describes a novel methodology to perform bilingual terminology extraction, in which automatic alignment is used to improve the performance of terminology extraction for each language. The strengths of monolingual terminology extraction for each language are exploited to improve the performance of terminology extraction in the other language, thanks to the availability of a sentence-level aligned bilingual corpus, and an automatic noun phrase alignment mechanism. The experiment indicates that weaknesses in monolingual terminology extraction due to the limitation of resources in certain languages can be overcome by using another language which has no such limitation.

2006

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Generating Multiple-Choice Test Items from Medical Text: A Pilot Study
Nikiforos Karamanis | Le An Ha | Ruslan Mitkov
Proceedings of the Fourth International Natural Language Generation Conference

2005

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Building a WSD module within an MT system to enable interactive resolution in the user’s source language
Constantin Orasan | Ted Marshall | Robert Clark | Le An Ha | Ruslan Mitkov
Proceedings of the 10th EAMT Conference: Practical applications of machine translation

2004

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A Practical Comparison of Different Filters Used in Automatic Term Extraction
Le An Ha
Proceedings of the Fourth International Conference on Language Resources and Evaluation (LREC’04)

2003

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Computer-Aided Generation of Multiple-Choice Tests
Ruslan Mitkov | Le An Ha
Proceedings of the HLT-NAACL 03 Workshop on Building Educational Applications Using Natural Language Processing

2002

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Learning description of term patterns using glossary resources
Le An Ha
Proceedings of the Third International Conference on Language Resources and Evaluation (LREC’02)