Inductive Learning
Healing Unsafe Dialogue Responses with Weak Supervision Signals
Liang, Zi, Wang, Pinghui, Zhang, Ruofei, Zhang, Shuo, Huang, Xiaofan Ye Yi, Feng, Junlan
Recent years have seen increasing concerns about the unsafe response generation of large-scale dialogue systems, where agents will learn offensive or biased behaviors from the real-world corpus. Some methods are proposed to address the above issue by detecting and replacing unsafe training examples in a pipeline style. Though effective, they suffer from a high annotation cost and adapt poorly to unseen scenarios as well as adversarial attacks. Besides, the neglect of providing safe responses (e.g. simply replacing with templates) will cause the information-missing problem of dialogues. To address these issues, we propose an unsupervised pseudo-label sampling method, TEMP, that can automatically assign potential safe responses. Specifically, our TEMP method groups responses into several clusters and samples multiple labels with an adaptively sharpened sampling strategy, inspired by the observation that unsafe samples in the clusters are usually few and distribute in the tail. Extensive experiments in chitchat and task-oriented dialogues show that our TEMP outperforms state-of-the-art models with weak supervision signals and obtains comparable results under unsupervised learning settings.
XTREME-UP: A User-Centric Scarce-Data Benchmark for Under-Represented Languages
Ruder, Sebastian, Clark, Jonathan H., Gutkin, Alexander, Kale, Mihir, Ma, Min, Nicosia, Massimo, Rijhwani, Shruti, Riley, Parker, Sarr, Jean-Michel A., Wang, Xinyi, Wieting, John, Gupta, Nitish, Katanova, Anna, Kirov, Christo, Dickinson, Dana L., Roark, Brian, Samanta, Bidisha, Tao, Connie, Adelani, David I., Axelrod, Vera, Caswell, Isaac, Cherry, Colin, Garrette, Dan, Ingle, Reeve, Johnson, Melvin, Panteleev, Dmitry, Talukdar, Partha
Data scarcity is a crucial issue for the development of highly multilingual NLP systems. Yet for many under-represented languages (ULs) -- languages for which NLP re-search is particularly far behind in meeting user needs -- it is feasible to annotate small amounts of data. Motivated by this, we propose XTREME-UP, a benchmark defined by: its focus on the scarce-data scenario rather than zero-shot; its focus on user-centric tasks -- tasks with broad adoption by speakers of high-resource languages; and its focus on under-represented languages where this scarce-data scenario tends to be most realistic. XTREME-UP evaluates the capabilities of language models across 88 under-represented languages over 9 key user-centric technologies including ASR, OCR, MT, and information access tasks that are of general utility. We create new datasets for OCR, autocomplete, semantic parsing, and transliteration, and build on and refine existing datasets for other tasks. XTREME-UP provides methodology for evaluating many modeling scenarios including text-only, multi-modal (vision, audio, and text),supervised parameter tuning, and in-context learning. We evaluate commonly used models on the benchmark. We release all code and scripts to train and evaluate models
Understanding Label Bias in Single Positive Multi-Label Learning
Arroyo, Julio, Perona, Pietro, Cole, Elijah
Annotating data for multi-label classification is prohibitively expensive because every category of interest must be confirmed to be present or absent. Recent work on single positive multi-label (SPML) learning shows that it is possible to train effective multi-label classifiers using only one positive label per image. However, the standard benchmarks for SPML are derived from traditional multi-label classification datasets by retaining one positive label for each training example (chosen uniformly at random) and discarding all other labels. In realistic settings it is not likely that positive labels are chosen uniformly at random. This work introduces protocols for studying label bias in SPML and provides new empirical results.
Context-Aware Transformer Pre-Training for Answer Sentence Selection
Di Liello, Luca, Garg, Siddhant, Moschitti, Alessandro
Answer Sentence Selection (AS2) is a core component for building an accurate Question Answering pipeline. AS2 models rank a set of candidate sentences based on how likely they answer a given question. The state of the art in AS2 exploits pre-trained transformers by transferring them on large annotated datasets, while using local contextual information around the candidate sentence. In this paper, we propose three pre-training objectives designed to mimic the downstream fine-tuning task of contextual AS2. This allows for specializing LMs when fine-tuning for contextual AS2. Our experiments on three public and two large-scale industrial datasets show that our pre-training approaches (applied to RoBERTa and ELECTRA) can improve baseline contextual AS2 accuracy by up to 8% on some datasets.
TaxoKnow: Taxonomy as Prior Knowledge in the Loss Function of Multi-class Classification
Pourvali, Mohsen, Meng, Yao, Sheng, Chen, Du, Yangzhou
Chiriatti 2020), have made significant advances in Natural Language Processing (NLP). In general, pre-training, where a model first trains on massive amounts of data before being fine-tuned for a specific task, has proven to be assumption in the real world. Moreover, compared to human an efficient technique for improving the performance of a capabilities, DNNs still lack in various aspects, such wide range of language tasks (Min et al. 2021). For example, as Adaptability, Generalizability, Robustness, Explainability, BERT (Devlin et al. 2018) is a pre-trained transformerbased Abstraction, Common sense, and Causal reasoning. In encoder model that can be fine-tuned for various NLP general, Multi-Layer Perceptrons (MLPs) are good at generalizing tasks, such as sentence classification, question answering, within the space of training examples, but they perform and named entity recognition. In fact, large language models poorly at generalizing outside the space of training examples, have shown a so-called few-shot learning capability to be and this limitation is not improved even by adding efficiently adapted to downstream tasks.
Data Curation Alone Can Stabilize In-context Learning
In-context learning (ICL) enables large language models (LLMs) to perform new tasks by prompting them with a sequence of training examples. However, it is known that ICL is very sensitive to the choice of training examples: randomly sampling examples from a training set leads to high variance in performance. In this paper, we show that carefully curating a subset of training data greatly stabilizes ICL performance without any other changes to the ICL algorithm (e.g., prompt retrieval or calibration). We introduce two methods to choose training subsets -- both score training examples individually, then select the highest-scoring ones. CondAcc scores a training example by its average dev-set ICL accuracy when combined with random training examples, while Datamodels learns linear regressors that estimate how the presence of each training example influences LLM outputs. Across five tasks and two LLMs, sampling from stable subsets selected by CondAcc and Datamodels improves average accuracy over sampling from the entire training set by 7.7% and 6.3%, respectively. Surprisingly, the stable subset examples are not especially diverse in content or low in perplexity, in contrast with other work suggesting that diversity and perplexity are important when prompting LLMs.
A Semi-Supervised Learning Approach for Ranging Error Mitigation Based on UWB Waveform
Li, Yuxiao, Mazuelas, Santiago, Shen, Yuan
Localization systems based on ultra-wide band (UWB) measurements can have unsatisfactory performance in harsh environments due to the presence of non-line-of-sight (NLOS) errors. Learning-based methods for error mitigation have shown great performance improvement via directly exploiting the wideband waveform instead of handcrafted features. However, these methods require data samples fully labeled with actual measurement errors for training, which leads to time-consuming data collection. In this paper, we propose a semi-supervised learning method based on variational Bayes for UWB ranging error mitigation. Combining deep learning techniques and statistic tools, our method can efficiently accumulate knowledge from both labeled and unlabeled data samples. Extensive experiments illustrate the effectiveness of the proposed method under different supervision rates, and the superiority compared to other fully supervised methods even at a low supervision rate.
Weakly Supervised AUC Optimization: A Unified Partial AUC Approach
Xie, Zheng, Liu, Yu, He, Hao-Yuan, Li, Ming, Zhou, Zhi-Hua
Since acquiring perfect supervision is usually difficult, real-world machine learning tasks often confront inaccurate, incomplete, or inexact supervision, collectively referred to as weak supervision. In this work, we present WSAUC, a unified framework for weakly supervised AUC optimization problems, which covers noisy label learning, positive-unlabeled learning, multi-instance learning, and semi-supervised learning scenarios. Within the WSAUC framework, we first frame the AUC optimization problems in various weakly supervised scenarios as a common formulation of minimizing the AUC risk on contaminated sets, and demonstrate that the empirical risk minimization problems are consistent with the true AUC. Then, we introduce a new type of partial AUC, specifically, the reversed partial AUC (rpAUC), which serves as a robust training objective for AUC maximization in the presence of contaminated labels. WSAUC offers a universal solution for AUC optimization in various weakly supervised scenarios by maximizing the empirical rpAUC. Theoretical and experimental results under multiple settings support the effectiveness of WSAUC on a range of weakly supervised AUC optimization tasks.
GRILL: Grounded Vision-language Pre-training via Aligning Text and Image Regions
Jin, Woojeong, Mukherjee, Subhabrata, Cheng, Yu, Shen, Yelong, Chen, Weizhu, Awadallah, Ahmed Hassan, Jose, Damien, Ren, Xiang
Generalization to unseen tasks is an important ability for few-shot learners to achieve better zero-/few-shot performance on diverse tasks. However, such generalization to vision-language tasks including grounding and generation tasks has been under-explored; existing few-shot VL models struggle to handle tasks that involve object grounding and multiple images such as visual commonsense reasoning or NLVR2. In this paper, we introduce GRILL, GRounded vIsion Language aLigning, a novel VL model that can be generalized to diverse tasks including visual question answering, captioning, and grounding tasks with no or very few training instances. Specifically, GRILL learns object grounding and localization by exploiting object-text alignments, which enables it to transfer to grounding tasks in a zero-/few-shot fashion. We evaluate our model on various zero-/few-shot VL tasks and show that it consistently surpasses the state-of-the-art few-shot methods.
Out-of-Distribution Generalization in Text Classification: Past, Present, and Future
Yang, Linyi, Song, Yaoxiao, Ren, Xuan, Lyu, Chenyang, Wang, Yidong, Liu, Lingqiao, Wang, Jindong, Foster, Jennifer, Zhang, Yue
Machine learning (ML) systems in natural language processing (NLP) face significant challenges in generalizing to out-of-distribution (OOD) data, where the test distribution differs from the training data distribution. This poses important questions about the robustness of NLP models and their high accuracy, which may be artificially inflated due to their underlying sensitivity to systematic biases. Despite these challenges, there is a lack of comprehensive surveys on the generalization challenge from an OOD perspective in text classification. Therefore, this paper aims to fill this gap by presenting the first comprehensive review of recent progress, methods, and evaluations on this topic. We furth discuss the challenges involved and potential future research directions. By providing quick access to existing work, we hope this survey will encourage future research in this area.