Delving Deeper into Cross-lingual Visual Question Answering

Visual question answering (VQA) is one of the crucial vision-and-language tasks. Yet, existing VQA research has mostly focused on the English language, due to a lack of suitable evaluation resources. Previous work on cross-lingual VQA has reported poor zero-shot transfer performance of current multilingual multimodal Transformers with large gaps to monolingual performance, without any deeper analysis. In this work, we delve deeper into the different aspects of cross-lingual VQA, aiming to understand the impact of 1) modeling methods and choices, including architecture, inductive bias, fine-tuning; 2) learning biases: including question types and modality biases in cross-lingual setups. The key results of our analysis are: 1) We show that simple modifications to the standard training setup can substantially reduce the transfer gap to monolingual English performance, yielding +10 accuracy points over existing methods. 2) We analyze cross-lingual VQA across different question types of varying complexity for different multilingual multimodal Transformers, and identify question types that are the most difficult to improve on. 3) We provide an analysis of modality biases present in training data and models, revealing why zero-shot performance gaps remain for certain question types and languages.Comment: Findings of EACL 202

Large Language Model Alignment: A Survey

Recent years have witnessed remarkable progress made in large language models (LLMs). Such advancements, while garnering significant attention, have concurrently elicited various concerns. The potential of these models is undeniably vast; however, they may yield texts that are imprecise, misleading, or even detrimental. Consequently, it becomes paramount to employ alignment techniques to ensure these models to exhibit behaviors consistent with human values. This survey endeavors to furnish an extensive exploration of alignment methodologies designed for LLMs, in conjunction with the extant capability research in this domain. Adopting the lens of AI alignment, we categorize the prevailing methods and emergent proposals for the alignment of LLMs into outer and inner alignment. We also probe into salient issues including the models' interpretability, and potential vulnerabilities to adversarial attacks. To assess LLM alignment, we present a wide variety of benchmarks and evaluation methodologies. After discussing the state of alignment research for LLMs, we finally cast a vision toward the future, contemplating the promising avenues of research that lie ahead. Our aspiration for this survey extends beyond merely spurring research interests in this realm. We also envision bridging the gap between the AI alignment research community and the researchers engrossed in the capability exploration of LLMs for both capable and safe LLMs.Comment: 76 page

Ranking and Retrieval under Semantic Relevance

This thesis presents a series of conceptual and empirical developments on the ranking and retrieval of candidates under semantic relevance. Part I of the thesis introduces the concept of uncertainty in various semantic tasks (such as recognizing textual entailment) in natural language processing, and the machine learning techniques commonly employed to model these semantic phenomena. A unified view of ranking and retrieval will be presented, and the trade-off between model expressiveness, performance, and scalability in model design will be discussed. Part II of the thesis focuses on applying these ranking and retrieval techniques to text: Chapter 3 examines the feasibility of ranking hypotheses given a premise with respect to a human's subjective probability of the hypothesis happening, effectively extending the traditional categorical task of natural language inference. Chapter 4 focuses on detecting situation frames for documents using ranking methods. Then we extend the ranking notion to retrieval, and develop both sparse (Chapter 5) and dense (Chapter 6) vector-based methods to facilitate scalable retrieval for potential answer paragraphs in question answering. Part III turns the focus to mentions and entities in text, while continuing the theme on ranking and retrieval: Chapter 7 discusses the ranking of fine-grained types that an entity mention could belong to, leading to state-of-the-art performance on hierarchical multi-label fine-grained entity typing. Chapter 8 extends the semantic relation of coreference to a cross-document setting, enabling models to retrieve from a large corpus, instead of in a single document, when resolving coreferent entity mentions

Evaluating Large Language Models: A Comprehensive Survey

Large language models (LLMs) have demonstrated remarkable capabilities across a broad spectrum of tasks. They have attracted significant attention and been deployed in numerous downstream applications. Nevertheless, akin to a double-edged sword, LLMs also present potential risks. They could suffer from private data leaks or yield inappropriate, harmful, or misleading content. Additionally, the rapid progress of LLMs raises concerns about the potential emergence of superintelligent systems without adequate safeguards. To effectively capitalize on LLM capacities as well as ensure their safe and beneficial development, it is critical to conduct a rigorous and comprehensive evaluation of LLMs. This survey endeavors to offer a panoramic perspective on the evaluation of LLMs. We categorize the evaluation of LLMs into three major groups: knowledge and capability evaluation, alignment evaluation and safety evaluation. In addition to the comprehensive review on the evaluation methodologies and benchmarks on these three aspects, we collate a compendium of evaluations pertaining to LLMs' performance in specialized domains, and discuss the construction of comprehensive evaluation platforms that cover LLM evaluations on capabilities, alignment, safety, and applicability. We hope that this comprehensive overview will stimulate further research interests in the evaluation of LLMs, with the ultimate goal of making evaluation serve as a cornerstone in guiding the responsible development of LLMs. We envision that this will channel their evolution into a direction that maximizes societal benefit while minimizing potential risks. A curated list of related papers has been publicly available at https://github.com/tjunlp-lab/Awesome-LLMs-Evaluation-Papers.Comment: 111 page

Democratizing Information Access through Low Overhead Systems

Despite its importance, accessing information in storage systems or raw data is challenging or impossible for most people due to the sheer amount and heterogeneity of data as well as the overheads and complexities of existing systems. In this thesis, we propose several approaches to improve on that and therefore democratize information access. Data-driven and AI based approaches make it possible to provide the necessary information access for many tasks at scale. Unfortunately, most existing approaches can only be built and used by IT experts and data scientists, yet the current demand for data scientists cannot be met by far. Furthermore, their application is expensive. To counter this, approaches with low overhead, i.e., without the need for large amounts of training data, manually annotating or extracting information, and extensive computation are needed. However, such systems still need to adapt to special terminology of different domains, and the individual information needs of the users. Moreover, they should be usable without extensive training; we thus aim to create ready-to-use systems that provide intuitive or familiar ways for interaction, e.g., chatbot-like natural language input or graphical user interfaces. In this thesis, we propose a number of contributions to three important subfields of data exploration and processing: Natural Language Interfaces for Data Access & Manipulation, Personalized Summarizations of Text Collections, and Information Extraction & Integration. These approaches allow data scientists, domain experts and end users to access and manipulate information in a quick and easy way. First, we propose two natural language interfaces for data access and manipulation. Natural language is a useful alternative interface for relational databases, since it allows users to formulate complex questions without requiring knowledge of SQL. We propose an approach based on weak supervision that augments existing deep learning techniques in order to improve the performance of models for natural language to SQL translation. Moreover, we apply the idea to build a training pipeline for conversational agents (i.e., chatbot-like systems allowing to interact with a database and perform actions like ticket booking). The pipeline uses weak supervision to generate the training data automatically from a relational database and its set of defined transactions. Our approach is data-aware, i.e., it leverages the data characteristics of the DB at runtime to optimize the dialogue flow and reduce necessary interactions. Additionally, we complement this research by presenting a meta-study on the reproducibility and availability of natural language interfaces for databases (NLIDBs) for real-world applications, and a benchmark to evaluate the linguistic robustness of NLIDBs. Second, we work on personalized summarization and its usage for data exploration. The central idea is to produce summaries that exactly cover the current information need of the users. By creating multiple summaries or shifting the focus during the interactive creation process, these summaries can be used to explore the contents of unknown text collections. We propose an approach to create such personalized summaries at interactive speed; this is achieved by carefully sampling from the inputs. As part of our research on multi-document summary, we noticed that there is a lack of diverse evaluation corpora for this task. We therefore present a framework that can be used to automatically create new summarization corpora, and apply and validate it. Third, we provide ways to democratize information extraction and integration. This becomes relevant when data is scattered across different sources and there is no tabular representation that already contains all information needed. Therefore, it might be necessary to integrate different structured sources, or to even extract the required information pieces from text collections first and then to organize them. To integrate existing structured data sources, we present and evaluate a novel end-to-end approach for schema matching based on neural embeddings. Finally, we tackle the automatic creation of tables from text for situations where no suitable structured source to answer an information need is available. Our proposed approach can execute SQL-like queries on text collections in an ad-hoc manner, both to directly extract facts from text documents, and to produce aggregated tables stating information that is not explicitly mentioned in the documents. Our approach works by generalizing user feedback and therefore does not need domain-specific resources for the domain adaption. It runs at interactive speed even on commodity hardware. Overall, our approaches can provide a quality level compared to state-of-the-art approaches, but often at a fraction of the associated costs. In other fields like the table extractions, we even provide functionality that is—to our knowledge—not covered by any generic tooling available to end users. There are still many interesting challenges to solve, and the recent rise of large language models has shifted what seems possible with regard to dealing with human language once more. Yet, we hope that our contributions provide a useful step towards democratization of information access