Papers by Howard Chen
Query-Focused Retrieval Heads Improve Long-Context Reasoning and Re-ranking (2025.emnlp-main)
Copied to clipboard
| Challenge: | Recent work has identified retrieval heads as a subset of attention heads responsible for retrieving salient information in long-context language models. |
| Approach: | They introduce a retrieval head that uses attention scores to enhance retrieval from long context . they use QRRetriever to select the most relevant parts with the highest retrieval scores . |
| Outcome: | The proposed retrieval heads outperform other retrieval-based retrieval retrievers on BEIR benchmarks. |
What In-Context Learning “Learns” In-Context: Disentangling Task Recognition and Task Learning (2023.findings-acl)
Copied to clipboard
| Challenge: | Large language models (LLMs) can perform in-context learning (ICL) with only a few demonstrations, but its mechanisms are not well-understood. |
| Approach: | They characterize two ways in which LLMs leverage demonstrations to solve tasks with a few demonstrations. |
| Outcome: | The proposed model achieves non-trivial performance with only TR, and TR does not improve with larger models or more demonstrations. |
How to Train Long-Context Language Models (Effectively) (2025.acl-long)
Copied to clipboard
| Challenge: | a new study shows that language models can process extremely long contexts with minimal training. |
| Approach: | They use supervised fine-tuning and continued training to evaluate a language model's long-context capabilities. |
| Outcome: | The proposed model outperforms Llama-3.1-8B-Instruct on most long-context tasks . the model can process 512K tokens, one of the longest context windows of LMs . |
Interactive Classification by Asking Informative Questions (2020.acl-main)
Copied to clipboard
| Challenge: | Existing methods for intent classification rely on a single user input and do not interact with the user to reduce ambiguity and improve the final prediction. |
| Approach: | They propose a limited form of interaction to natural language intent classification . they add binary or multi-choice questions to the system to ask missing information . |
| Outcome: | The proposed method can be bootstrapped without interaction data and is scalable to two domains. |
Autoregressive Knowledge Distillation through Imitation Learning (2020.emnlp-main)
Copied to clipboard
| Challenge: | Autoregressive models are ubiquitous in natural language processing due to the sequential nature of text generation. |
| Approach: | They propose a compression technique for autoregressive models driven by an imitation learning perspective on knowledge distillation. |
| Outcome: | The proposed method outperforms other distillation algorithms on translation and summarization tasks while increasing inference speed 14 times. |
Non-Parametric Few-Shot Learning for Word Sense Disambiguation (2021.naacl-main)
Copied to clipboard
| Challenge: | Word sense disambiguation (WSD) is a problem in natural language processing . 84% of annotated words have less than 10 examples in the long-tail distribution . |
| Approach: | They propose a non-parametric few-shot learning approach to mitigate word sense disambiguation . they use a metric space to compute distances among the senses of a given word . |
| Outcome: | The proposed method achieves a 75.1 F1 score on the unified evaluation benchmark. |
Action-Based Conversations Dataset: A Corpus for Building More In-Depth Task-Oriented Dialogue Systems (2021.naacl-main)
Copied to clipboard
| Challenge: | Existing goal-oriented dialogue datasets focus on identifying slots and values, but in reality, customer service agents follow multi-step procedures derived from explicit company policies. |
| Approach: | They propose to use a fully-labeled dataset to study customer service dialogue systems in real-world scenarios. |
| Outcome: | The proposed dataset outperforms existing models but still lacks 50.8% absolute accuracy to reach human-level performance on the dataset. |
Can Rationalization Improve Robustness? (2022.naacl-main)
Copied to clipboard
| Challenge: | Existing models that generate rationales before making predictions can ignore noise or adversarially added text by simply masking it out of the generated rationale. |
| Approach: | They propose to use a 'rationalizethen-predict' framework to generate subsets of input to generate rationales and then make predictions using them. |
| Outcome: | The proposed models improve robustness over AddText attacks while struggling in certain scenarios. |
Enabling Large Language Models to Generate Text with Citations (2023.emnlp-main)
Copied to clipboard
| Challenge: | Existing work relies on commercial search engines and human evaluation, making it difficult to reproduce and compare different modeling approaches. |
| Approach: | They propose a new generation paradigm that requires large language models to provide citations to one or a few text passages for any statement they generate. |
| Outcome: | The proposed model improves factual correctness and verifiability of large language models by providing citations to a set of questions and retrieval corpora and generating answers with citation. |
C-STS: Conditional Semantic Textual Similarity (2023.emnlp-main)
Copied to clipboard
Ameet Deshpande, Carlos Jimenez, Howard Chen, Vishvak Murahari, Victoria Graf, Tanmay Rajpurohit, Ashwin Kalyan, Danqi Chen, Karthik Narasimhan
| Challenge: | Semantic textual similarity (STS) is a cornerstone task in natural language processing, but it is inherently ambiguous. |
| Approach: | They propose a task called conditional STS which measures similarity conditioned on an aspect elucidated in natural language. |
| Outcome: | The proposed task reduces subjectivity and ambiguity and enables fine-grained similarity evaluation using diverse conditions. |
Long-Context Language Modeling with Parallel Context Encoding (2024.acl-long)
Copied to clipboard
| Challenge: | Existing long-context models degenerate with retrieved contexts. |
| Approach: | They propose a framework that can be applied to existing decoder-only LLMs for context expansion. |
| Outcome: | The proposed framework can be applied to any existing decoder-only LLMs for context expansion. |