Idan Szpektor
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As instruction-tuned large language models (LLMs) gain global adoption, their ability to follow instructions in multiple languages becomes increasingly crucial. In this work, we investigate how multilinguality during instruction tuning of a multilingual LLM affects instruction-following across languages from the pre-training corpus. We first show that many languages transfer some instruction-following capabilities to other languages from even monolingual tuning. Furthermore, we find that only 40 multilingual examples integrated in an English tuning set substantially improve multilingual instruction-following, both in seen and unseen languages during tuning. In general, we observe that models tuned on multilingual mixtures exhibit comparable or superior performance in multiple languages compared to monolingually tuned models, despite training on 10x fewer examples in those languages. Finally, we find that diversifying the instruction tuning set with even just 2-4 languages significantly improves cross-lingual generalization. Our results suggest that building massively multilingual instruction-tuned models can be done with only a very small set of multilingual instruction-responses.
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Factually Consistent Summarization via Reinforcement Learning with Textual Entailment Feedback
Paul Roit
Johan Ferret
Geoffrey Cideron
Matthieu Geist
Sertan Girgin
Léonard Hussenot
Nikola Momchev
Piotr Stanczyk
Nino Vieillard
Olivier Pietquin
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics, Association for Computational Linguistics (2023), 6252–6272
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Despite the seeming success of contemporary grounded text generation systems, they often tend to generate factually inconsistent text with respect to their input. This phenomenon is emphasized in tasks like summarization, in which the generated summaries should be corroborated by their source article. In this work we leverage recent progress on textual entailment models to directly address this problem for abstractive summarization systems. We use reinforcement learning with reference-free, textual-entailment rewards to optimize for factual consistency and explore the ensuing trade-offs, as improved consistency may come at the cost of less informative or more extractive summaries. Our results, according to both automatic metrics and human evaluation, show that our method considerably improves the faithfulness, salience and conciseness of the generated summaries.
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Most works on modeling the conversation history in Conversational Question Answering (CQA) report a single main result on a common CQA benchmark. While existing models show impressive results on CQA leaderboards, it remains unclear whether they are robust to shifts in setting (sometimes to more realistic ones), training data size (e.g. from large to small sets) and domain. In this work, we design and conduct the first large-scale robustness study of history modeling approaches for CQA. We find that high benchmark scores do not necessarily translate to strong robustness, and that various methods can perform extremely differently under different settings. Equipped with the insights from our study, we design a novel prompt-based history modeling approach, and demonstrate its strong robustness across various settings. Our approach is inspired by existing methods that highlight historic answers in the passage. However, instead of highlighting by modifying the passage token embeddings, we add textual prompts directly in the passage text. Our approach is simple, easy-to-plug into practically any model, and highly effective, thus we recommend it as a starting point for future model developers. We also hope that our study and insights will raise awareness to the importance of robustness-focused evaluation, in addition to obtaining high leaderboard scores, leading to better CQA systems.
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Text to image generation methods (T2I) are widely popular in generating art and other creative artifacts.
While hallucination can be a positive factor in scenarios where creativity is appreciated, such artifacts are poorly suited for tasks where the generated image needs to be grounded in a strict manner, e.g. as an illustration of a task, an action or in the context of a story.
In this paper, we propose to strengthen the factual consistency properties of T2I methods in the presence of natural prompts.
First, we cast the problem as an MT problem that translates natural prompts into visual prompts. Then we filter the image with a VQA approach where we answer a set of questions in the visual domain (the image) and in the natural language domain (the natural prompt).
Finally, to measure the alignment of answers, we depart from the recent literature that do string matching, and compare answers in an embedding space that assesses the semantic and entailment associations between a natural prompt and its generated image.
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The alignment of diverse data modalities, especially video and text, is a significant challenge in AI. This study introduces VideoCon, a novel dataset for robust video-language alignment evaluation. It provides contrast captions for originally matched video-captions, complemented with natural language explanations (NLEs) that delineate the differences between the video and the contrast captions. Notably, VideoCon emphasizes temporally challenging scenarios to enhance the robustness of evaluations. To address misalignments observed in previous models, we propose AlignVideo, a video-language model trained on VideoCon that demonstrates enhanced alignment capabilities. Experiments reveal that AlignVideo surpasses existing baselines in video-text alignment and generates more precise NLEs. Moreover, it showcases state-of-the-art performance in zero-shot downstream tasks, emphasizing complex video understanding, such as action recognition and temporal event sequencing. Our work paves the way for advancements in video-text alignment evaluation and model development.
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We address the task of sentence retrieval for open-ended dialogues.The goal is to retrieve sentences from a document corpus that con-tain information useful for generating the next turn in a givendialogue. To this end, we propose several novel architectures fordual contextual modeling: the dialogue context and the context ofthe sentence in its ambient document. The architectures utilize fine-tuned contextualized language models (BERT). We are not aware ofprevious work that modeled the context of the sentence (passage)to be retrieved in a dialogue setting. Furthermore, some of the tech-niques we present for modeling the dialogue context are novel tothis study. To evaluate the models, we constructed a test-set thatincludes open-ended dialogues from Reddit, candidate sentencesfrom Wikipedia for each dialogue and human annotations for thesentences. To train the neural-based models, we devised a weaksupervision method applied to a large-scale Reddit dataset. Weempirically compared our models with a wide array of strong ref-erence comparisons. The performance of our most effective modelis substantially superior to that of all baselines, demonstrating themerits of our novel architectures and weakly-supervised trainingapproach.
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Factual consistency evaluation is often conducted using Natural Language Inference (NLI) models, yet these models exhibit limited success in evaluating summaries. Previous work improved such models with synthetic training data. However, the data is typically based on perturbed human-written summaries, which often differ in their characteristics from real model-generated summaries and have limited coverage of possible factual errors. Alternatively, large language models (LLMs) have recently shown promising results in directly evaluating generative tasks, but are too computationally expensive for practical use. Motivated by these limitations, we introduce TrueTeacher, a method for generating synthetic data by annotating diverse model-generated summaries using a LLM. Unlike prior work, TrueTeacher does not rely on human-written summaries, and is multilingual by nature. Experiments on the TRUE benchmark show that a student model trained using our data, substantially outperforms both the state-of-the-art model with similar capacity, and the LLM teacher. In a systematic study, we compare TrueTeacher to existing synthetic data generation methods and demonstrate its superiority and robustness to domain-shift. We also show that our method generalizes to multilingual scenarios using the mFACE dataset. Finally, we release a large-scale synthetic dataset with 1.4M examples generated using TrueTeacher.
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MaXM: Towards Multilingual Visual Question Answering
Linting Xue
Michal Yarom
Findings of ACL: EMNLP (2023)
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Visual Question Answering (VQA) has been primarily studied through the lens of the English language. Yet, tackling VQA in other languages in the same manner would require a considerable amount of resources. In this paper, we propose scalable solutions to multilingual visual question answering (mVQA), on both data and modeling fronts. We first propose a translation-based framework to mVQA data generation that requires much less human annotation efforts than the conventional approach of directly collection questions and answers. Then, we apply our framework to the multilingual captions in the Crossmodal-3600 dataset and develop an efficient annotation protocol to create MaXM, a test-only VQA benchmark in 7 diverse languages. Finally, we develop a simple, lightweight, and effective approach as well as benchmark state-of-the-art English and multilingual VQA models. We hope that our benchmark encourages further research on mVQA.
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Mismatch Quest: Visual and Textual Feedback for Image-Text Misalignment
Brian Gordon
Dani Lischinski
Daniel Cohen-Or
arXiv (2023)
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While existing image/text alignment models reach high quality binary assessments, they fall short of pinpointing the exact source of misalignment.
In this paper, we present a method to provide detailed textual and visual explanation of detected misalignments between text/image pairs.
We leverage large language models to automatically construct a training set that holds plausible misaligned captions for a given image and corresponding textual explanations and visual indicators. We also introduce a new human curated test set comprising ground-truth textual and visual misalignment annotations. Empirical results show that fine-tuning vision language models on our training set enables them to articulate misalignments and visually indicate them within images, outperforming strong baselines both on the binary alignment classification and the explanation generation tasks.
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What You See is What You Read? Improving Text-Image Alignment Evaluation
Michal Yarom
Eran Ofek
arXiv (2023)
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Automatically determining whether a text and a corresponding image are semantically aligned is a significant challenge for vision-language models, with applications in generative text-to-image and image-to-text tasks. In this work, we study methods for automatic image-text alignment evaluation. We first introduce a comprehensive evaluation set spanning multiple datasets from both text-to-image and image-to-text generation tasks, with human judgements for whether a given text-image pair is semantically aligned. We then describe two automatic methods to determine alignment: the first involving a pipeline based on question generation and visual question answering models, and the second employing an end-to-end classification approach based on synthetic data generation. Both methods surpass prior approaches in various text-image alignment tasks, with our analysis showing significant improvements in challenging cases that involve complex composition or unnatural images. Finally, we demonstrate how our approaches can localize specific misalignments between an image and a given text, and how they can be used to automatically re-rank candidates in text-to-image generation.
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