Rohini K. Srihari

Also published as: K. Rohini Srihari, Rohini Srihari


2024

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Improving Dialog Safety using Socially Aware Contrastive Learning
Souvik Das | Rohini K. Srihari
Proceedings of the 1st Workshop on Simulating Conversational Intelligence in Chat (SCI-CHAT 2024)

State-of-the-art conversational AI systems raise concerns due to their potential risks of generating unsafe, toxic, unethical, or dangerous content. Previous works have developed datasets to teach conversational agents the appropriate social paradigms to respond effectively to specifically designed hazardous content. However, models trained on these adversarial datasets still struggle to recognize subtle unsafe situations that appear naturally in conversations or introduce an inappropriate response in a casual context. To understand the extent of this problem, we study prosociality in both adversarial and casual dialog contexts and audit the response quality of general-purpose language models in terms of propensity to produce unsafe content. We propose a dual-step fine-tuning process to address these issues using a socially aware n-pair contrastive loss. Subsequently, we train a base model that integrates prosocial behavior by leveraging datasets like Moral Integrity Corpus (MIC) and ProsocialDialog. Experimental results on several dialog datasets demonstrate the effectiveness of our approach in generating socially appropriate responses.

2023

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Rudolf Christoph Eucken at SemEval-2023 Task 4: An Ensemble Approach for Identifying Human Values from Arguments
Sougata Saha | Rohini Srihari
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

The subtle human values we acquire through life experiences govern our thoughts and gets reflected in our speech. It plays an integral part in capturing the essence of our individuality and making it imperative to identify such values in computational systems that mimic human actions. Computational argumentation is a field that deals with the argumentation capabilities of humans and can benefit from identifying such values. Motivated by that, we present an ensemble approach for detecting human values from argument text. Our ensemble comprises three models: (i) An entailment-based model for determining the human values based on their descriptions, (ii) A Roberta-based classifier that predicts the set of human values from an argument. (iii) A Roberta-based classifier to predict a reduced set of human values from an argument. We experiment with different ways of combining the models and report our results. Furthermore, our best combination achieves an overall F1 score of 0.48 on the main test set.

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ArgU: A Controllable Factual Argument Generator
Sougata Saha | Rohini Srihari
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Effective argumentation is essential towards a purposeful conversation with a satisfactory outcome. For example, persuading someone to reconsider smoking might involve empathetic, well founded arguments based on facts and expert opinions about its ill-effects and the consequences on one’s family. However, the automatic generation of high-quality factual arguments can be challenging. Addressing existing controllability issues can make the recent advances in computational models for argument generation a potential solution. In this paper, we introduce ArgU: a neural argument generator capable of producing factual arguments from input facts and real-world concepts that can be explicitly controlled for stance and argument structure using Walton’s argument scheme-based control codes. Unfortunately, computational argument generation is a relatively new field and lacks datasets conducive to training. Hence, we have compiled and released an annotated corpora of 69,428 arguments spanning six topics and six argument schemes, making it the largest publicly available corpus for identifying argument schemes; the paper details our annotation and dataset creation framework. We further experiment with an argument generation strategy that establishes an inference strategy by generating an “argument template” before actual argument generation. Our results demonstrate that it is possible to automatically generate diverse arguments exhibiting different inference patterns for the same set of facts by using control codes based on argument schemes and stance.

2022

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EDU-AP: Elementary Discourse Unit based Argument Parser
Sougata Saha | Souvik Das | Rohini Srihari
Proceedings of the 23rd Annual Meeting of the Special Interest Group on Discourse and Dialogue

Neural approaches to end-to-end argument mining (AM) are often formulated as dependency parsing (DP), which relies on token-level sequence labeling and intricate post-processing for extracting argumentative structures from text. Although such methods yield reasonable results, operating solely with tokens increases the possibility of discontinuous and overly segmented structures due to minor inconsistencies in token level predictions. In this paper, we propose EDU-AP, an end-to-end argument parser, that alleviates such problems in dependency-based methods by exploiting the intrinsic relationship between elementary discourse units (EDUs) and argumentative discourse units (ADUs) and operates at both token and EDU level granularity. Further, appropriately using contextual information, along with optimizing a novel objective function during training, EDU-AP achieves significant improvements across all four tasks of AM compared to existing dependency-based methods.

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Diving Deep into Modes of Fact Hallucinations in Dialogue Systems
Souvik Das | Sougata Saha | Rohini Srihari
Findings of the Association for Computational Linguistics: EMNLP 2022

Knowledge Graph(KG) grounded conversations often use large pre-trained models and usually suffer from fact hallucination. Frequently entities with no references in knowledge sources and conversation history are introduced into responses, thus hindering the flow of the conversation—existing work attempt to overcome this issue by tweaking the training procedure or using a multi-step refining method. However, minimal effort is put into constructing an entity-level hallucination detection system, which would provide fine-grained signals that control fallacious content while generating responses. As a first step to address this issue, we dive deep to identify various modes of hallucination in KG-grounded chatbots through human feedback analysis. Secondly, we propose a series of perturbation strategies to create a synthetic dataset named FADE (FActual Dialogue Hallucination DEtection Dataset). Finally, we conduct comprehensive data analyses and create multiple baseline models for hallucination detection to compare against human-verified data and already established benchmarks.

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Proto-Gen: An end-to-end neural generator for persona and knowledge grounded response generation
Sougata Saha | Souvik Das | Rohini Srihari
Proceedings of the 1st Workshop on Customized Chat Grounding Persona and Knowledge

In this paper we detail the implementation of Proto-Gen, an end-to-end neural response generator capable of selecting appropriate persona and fact sentences from available options, and generating persona and fact grounded responses. Incorporating a novel interaction layer in an encoder-decoder architecture, Proto-Gen facilitates learning dependencies between facts, persona and the context, and outperforms existing baselines on the FoCus dataset for both the sub-tasks of persona and fact selection, and response generation. We further fine tune Proto-Gen’s hyperparameters, and share our results and findings.

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Using Multi-Encoder Fusion Strategies to Improve Personalized Response Selection
Souvik Das | Sougata Saha | Rohini K. Srihari
Proceedings of the 29th International Conference on Computational Linguistics

Personalized response selection systems are generally grounded on persona. However, a correlation exists between persona and empathy, which these systems do not explore well. Also, when a contradictory or off-topic response is selected, faithfulness to the conversation context plunges. This paper attempts to address these issues by proposing a suite of fusion strategies that capture the interaction between persona, emotion, and entailment information of the utterances. Ablation studies on the Persona-Chat dataset show that incorporating emotion and entailment improves the accuracy of response selection. We combine our fusion strategies and concept-flow encoding to train a BERT-based model which outperforms the previous methods by margins larger than 2.3% on original personas and 1.9% on revised personas in terms of hits@1 (top-1 accuracy), achieving a new state-of-the-art performance on the Persona-Chat dataset

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Dialo-AP: A Dependency Parsing Based Argument Parser for Dialogues
Sougata Saha | Souvik Das | Rohini K. Srihari
Proceedings of the 29th International Conference on Computational Linguistics

While neural approaches to argument mining (AM) have advanced considerably, most of the recent work has been limited to parsing monologues. With an urgent interest in the use of conversational agents for broader societal applications, there is a need to advance the state-of-the-art in argument parsers for dialogues. This enables progress towards more purposeful conversations involving persuasion, debate and deliberation. This paper discusses Dialo-AP, an end-to-end argument parser that constructs argument graphs from dialogues. We formulate AM as dependency parsing of elementary and argumentative discourse units; the system is trained using extensive pre-training and curriculum learning comprising nine diverse corpora. Dialo-AP is capable of generating argument graphs from dialogues by performing all sub-tasks of AM. Compared to existing state-of-the-art baselines, Dialo-AP achieves significant improvements across all tasks, which is further validated through rigorous human evaluation.

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Let’s Chat: Understanding User Expectations in Socialbot Interactions
Elizabeth Soper | Erin Pacquetet | Sougata Saha | Souvik Das | Rohini Srihari
Proceedings of the Second Workshop on Bridging Human--Computer Interaction and Natural Language Processing

This paper analyzes data from the 2021 Amazon Alexa Prize Socialbot Grand Challenge 4, in order to better understand the differences between human-computer interactions (HCI) in a socialbot setting and conventional human-to-human interactions. We find that because socialbots are a new genre of HCI, we are still negotiating norms to guide interactions in this setting. We present several notable patterns in user behavior toward socialbots, which have important implications for guiding future work in the development of conversational agents.

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Similarity Based Label Smoothing For Dialogue Generation
Sougata Saha | Souvik Das | Rohini Srihari
Proceedings of the 19th International Conference on Natural Language Processing (ICON)

Generative neural conversational systems are typically trained by minimizing the entropy loss between the training “hard” targets and the predicted logits. Performance gains and improved generalization are often achieved by employing regularization techniques like label smoothing, which converts the training “hard” targets to soft targets. However, label smoothing enforces a data independent uniform distribution on the incorrect training targets, leading to a false assumption of equiprobability. In this paper, we propose and experiment with incorporating data-dependent word similarity-based weighing methods to transform the uniform distribution of the incorrect target probabilities in label smoothing to a more realistic distribution based on semantics. We introduce hyperparameters to control the incorrect target distribution and report significant performance gains over networks trained using standard label smoothing-based loss on two standard open-domain dialogue corpora.

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Stylistic Response Generation by Controlling Personality Traits and Intent
Sougata Saha | Souvik Das | Rohini Srihari
Proceedings of the 4th Workshop on NLP for Conversational AI

Personality traits influence human actions and thoughts, which is manifested in day to day conversations. Although glimpses of personality traits are observable in existing open domain conversation corpora, leveraging generic language modelling for response generation overlooks the interlocutor idiosyncrasies, resulting in non-customizable personality agnostic responses. With the motivation of enabling stylistically configurable response generators, in this paper we experiment with end-to-end mechanisms to ground neural response generators based on both (i) interlocutor Big-5 personality traits, and (ii) discourse intent as stylistic control codes. Since most of the existing large scale open domain chat corpora do not include Big-5 personality traits and discourse intent, we employ automatic annotation schemes to enrich the corpora with noisy estimates of personality and intent annotations, and further assess the impact of using such features as control codes for response generation using automatic evaluation metrics, ablation studies and human judgement. Our experiments illustrate the effectiveness of this strategy resulting in improvements to existing benchmarks. Additionally, we yield two silver standard annotated corpora with intents and personality traits annotated, which can be of use to the research community.

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UB Health Miners@SMM4H’22: Exploring Pre-processing Techniques To Classify Tweets Using Transformer Based Pipelines.
Roshan Khatri | Sougata Saha | Souvik Das | Rohini Srihari
Proceedings of The Seventh Workshop on Social Media Mining for Health Applications, Workshop & Shared Task

Here we discuss our implementation of two tasks in the Social Media Mining for Health Applications (SMM4H) 2022 shared tasks – classification, detection, and normalization of Adverse Events (AE) mentioned in English tweets (Task 1) and classification of English tweets self-reporting exact age (Task 4). We have explored different methods and models for binary classification, multi-class classification and named entity recognition (NER) for these tasks. We have also processed the provided dataset for noise, imbalance, and creative language expression from data. Using diverse NLP methods we classified tweets for mentions of adverse drug effects (ADEs) and self-reporting the exact age in the tweets. Further, extracted reactions from the tweets and normalized these adverse effects to a standard concept ID in the MedDRA vocabulary.

2020

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Self-Supervised Claim Identification for Automated Fact Checking
Archita Pathak | Mohammad Abuzar Shaikh | Rohini Srihari
Proceedings of the 17th International Conference on Natural Language Processing (ICON)

We propose a novel, attention-based self-supervised approach to identify “claim-worthy” sentences in a fake news article, an important first step in automated fact-checking. We leverage aboutness of headline and content using attention mechanism for this task. The identified claims can be used for downstream task of claim verification for which we are releasing a benchmark dataset of manually selected compelling articles with veracity labels and associated evidence. This work goes beyond stylistic analysis to identifying content that influences reader belief. Experiments with three datasets show the strength of our model.

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Autobots Ensemble: Identifying and Extracting Adverse Drug Reaction from Tweets Using Transformer Based Pipelines
Sougata Saha | Souvik Das | Prashi Khurana | Rohini Srihari
Proceedings of the Fifth Social Media Mining for Health Applications Workshop & Shared Task

This paper details a system designed for Social Media Mining for Health Applications (SMM4H) Shared Task 2020. We specifically describe the systems designed to solve task 2: Automatic classification of multilingual tweets that report adverse effects, and task 3: Automatic extraction and normalization of adverse effects in English tweets. Fine tuning RoBERTa large for classifying English tweets enables us to achieve a F1 score of 56%, which is an increase of +10% compared to the average F1 score for all the submissions. Using BERT based NER and question answering, we are able to achieve a F1 score of 57.6% for extracting adverse reaction mentions from tweets, which is an increase of +1.2% compared to the average F1 score for all the submissions.

2019

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BREAKING! Presenting Fake News Corpus for Automated Fact Checking
Archita Pathak | Rohini Srihari
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics: Student Research Workshop

Popular fake news articles spread faster than mainstream articles on the same topic which renders manual fact checking inefficient. At the same time, creating tools for automatic detection is as challenging due to lack of dataset containing articles which present fake or manipulated stories as compelling facts. In this paper, we introduce manually verified corpus of compelling fake and questionable news articles on the USA politics, containing around 700 articles from Aug-Nov, 2016. We present various analyses on this corpus and finally implement classification model based on linguistic features. This work is still in progress as we plan to extend the dataset in the future and use it for our approach towards automated fake news detection.

2017

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Summarizing World Speak : A Preliminary Graph Based Approach
Nikhil Londhe | Rohini Srihari
Proceedings of the International Conference Recent Advances in Natural Language Processing, RANLP 2017

Social media platforms play a crucial role in piecing together global news stories via their corresponding online discussions. Thus, in this work, we introduce the problem of automatically summarizing massively multilingual microblog text streams. We discuss the challenges involved in both generating summaries as well as evaluating them. We introduce a simple word graph based approach that utilizes node neighborhoods to identify keyphrases and thus in turn, pick summary candidates. We also demonstrate the effectiveness of our method in generating precise summaries as compared to other popular techniques.

2016

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Time-Independent and Language-Independent Extraction of Multiword Expressions From Twitter
Nikhil Londhe | Rohini Srihari | Vishrawas Gopalakrishnan
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: Technical Papers

Multiword Expressions (MWEs) are crucial lexico-semantic units in any language. However, most work on MWEs has been focused on standard monolingual corpora. In this work, we examine MWE usage on Twitter - an inherently multilingual medium with an extremely short average text length that is often replete with grammatical errors. In this work we present a new graph based, language agnostic method for automatically extracting MWEs from tweets. We show how our method outperforms standard Association Measures. We also present a novel unsupervised evaluation technique to ascertain the accuracy of MWE extraction.

2012

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Analyzing Urdu Social Media for Sentiments using Transfer Learning with Controlled Translations
Smruthi Mukund | Rohini Srihari
Proceedings of the Second Workshop on Language in Social Media

2011

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Using Sequence Kernels to identify Opinion Entities in Urdu
Smruthi Mukund | Debanjan Ghosh | Rohini Srihari
Proceedings of the Fifteenth Conference on Computational Natural Language Learning

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Unsupervised Russian POS Tagging with Appropriate Context
Li Yang | Erik Peterson | John Chen | Yana Petrova | Rohini Srihari
Proceedings of the Fifth International Workshop On Cross Lingual Information Access

2010

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Using Cross-Lingual Projections to Generate Semantic Role Labeled Annotated Corpus for Urdu - A Resource Poor Language
Smruthi Mukund | Debanjan Ghosh | Rohini Srihari
Proceedings of the 23rd International Conference on Computational Linguistics (Coling 2010)

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A Vector Space Model for Subjectivity Classification in Urdu aided by Co-Training
Smruthi Mukund | Rohini Srihari
Coling 2010: Posters

2009

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NE Tagging for Urdu based on Bootstrap POS Learning
Smruthi Mukund | Rohini K. Srihari
Proceedings of the Third International Workshop on Cross Lingual Information Access: Addressing the Information Need of Multilingual Societies (CLIAWS3)

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Making Semantic Topicality Robust Through Term Abstraction
Paul M. Heider | Rohini K. Srihari
Proceedings of the Workshop on Semantic Evaluations: Recent Achievements and Future Directions (SEW-2009)

2006

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Automatically Extracting Nominal Mentions of Events with a Bootstrapped Probabilistic Classifier
Cassandre Creswell | Matthew J. Beal | John Chen | Thomas L. Cornell | Lars Nilsson | Rohini K. Srihari
Proceedings of the COLING/ACL 2006 Main Conference Poster Sessions

2005

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Word Independent Context Pair Classification Model for Word Sense Disambiguation
Cheng Niu | Wei Li | Rohini K. Srihari | Huifeng Li
Proceedings of the Ninth Conference on Computational Natural Language Learning (CoNLL-2005)

2004

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Weakly Supervised Learning for Cross-document Person Name Disambiguation Supported by Information Extraction
Cheng Niu | Wei Li | Rohini K. Srihari
Proceedings of the 42nd Annual Meeting of the Association for Computational Linguistics (ACL-04)

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Context clustering for Word Sense Disambiguation based on modeling pairwise context similarities
Cheng Niu | Wei Li | Rohini K. Srihari | Huifeng Li | Laurie Crist
Proceedings of SENSEVAL-3, the Third International Workshop on the Evaluation of Systems for the Semantic Analysis of Text

2003

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Bootstrapping for Named Entity Tagging Using Concept-based Seeds
Cheng Niu | Wei Li | Jihong Ding | Rohini K. Srihari
Companion Volume of the Proceedings of HLT-NAACL 2003 - Short Papers

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InfoXtract location normalization: a hybrid approach to geographic references in information extraction
Huifeng Li | K. Rohini Srihari | Cheng Niu | Wei Li
Proceedings of the HLT-NAACL 2003 Workshop on Analysis of Geographic References

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InfoXtract: A Customizable Intermediate Level Information Extraction Engine
Rohini K. Srihari | Wei Li | Cheng Niu | Thomas Cornell
Proceedings of the HLT-NAACL 2003 Workshop on Software Engineering and Architecture of Language Technology Systems (SEALTS)

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Question Answering on a Case Insensitive Corpus
Wei Li | Rohini Srihari | Cheng Niu | Xiaoge Li
Proceedings of the ACL 2003 Workshop on Multilingual Summarization and Question Answering

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A Bootstrapping Approach to Named Entity Classification Using Successive Learners
Cheng Niu | Wei Li | Jihong Ding | Rohini Srihari
Proceedings of the 41st Annual Meeting of the Association for Computational Linguistics

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An Expert Lexicon Approach to Identifying English Phrasal Verbs
Wei Li | Xiuhong Zhang | Cheng Niu | Yuankai Jiang | Rohini K. Srihari
Proceedings of the 41st Annual Meeting of the Association for Computational Linguistics

2002

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Location Normalization for Information Extraction
Huifeng Li | Rohini K. Srihari | Cheng Niu | Wei Li
COLING 2002: The 19th International Conference on Computational Linguistics

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Extracting Exact Answers to Questions Based on Structural Links
Wei Li | Rohini K. Srihari | Xiaoge Li | M. Srikanth | Xiuhong Zhang | Cheng Niu
COLING-02: Multilingual Summarization and Question Answering

2000

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A Question Answering System Supported by Information Extraction
Rohini Srihari | Wei Li
Sixth Applied Natural Language Processing Conference

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A Hybrid Approach for Named Entity and Sub-Type Tagging
Rohini Srihari
Sixth Applied Natural Language Processing Conference

1994

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Use of Lexical and Syntactic Techniques in Recognizing Handwritten Text
Rohini K. Srihari
Human Language Technology: Proceedings of a Workshop held at Plainsboro, New Jersey, March 8-11, 1994