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Alisa Liu

14 accepted papers

2025

Broken Tokens? Your Language Model can Secretly Handle Non-Canonical Tokenizations

NeurIPS 2025spotlight

Modern tokenizers employ deterministic algorithms to map text into a single ``canonical" token sequence, yet the same string can be encoded as many non-canonical tokenizations using the language model vocabulary, including tokenizing by character. In this paper, we investigate the robustness of LMs…

Cited by 0SourceScholar
2025

Does Liking Yellow Imply Driving a School Bus? Semantic Leakage in Language Models

NAACL 2025long

Despite their wide adoption, the biases and unintended behaviors of language models remain poorly understood. In this paper, we identify and characterize a phenomenon never discussed before, which we call semantic leakage, where models leak irrelevant information from the prompt into the generation…

Cited by 4SourcePDFScholar
2025

LlamaPIE: Proactive In-Ear Conversation Assistants

ACL 2025finding

We introduce LlamaPIE, the first real-time proactive assistant designed to enhance human conversations through discreet, concise guidance delivered via hearable devices. Unlike traditional language models that require explicit user invocation, this assistant operates in the background, anticipating…

2024

Data Mixture Inference Attack: BPE Tokenizers Reveal Training Data Compositions

NeurIPS 2024poster

The pretraining data of today's strongest language models remains opaque, even when their parameters are open-sourced. In particular, little is known about the proportions of different domains, languages, or code represented in the data. While a long line of membership inference attacks aim to ident…

Cited by 1SourcePDFScholar
2024

Decoding-Time Language Model Alignment with Multiple Objectives

NeurIPS 2024poster

Aligning language models (LMs) to human preferences has emerged as a critical pursuit, enabling these models to better serve diverse user needs. Existing methods primarily focus on optimizing LMs for a single reward function, limiting their adaptability to varied objectives. Here, we propose $\text…

2024

How Language Model Hallucinations Can Snowball

ICML 2024poster

A major risk of using language models in practical applications is their tendency to hallucinate incorrect statements. Hallucinations are often attributed to knowledge gaps in LMs, but we show that LMs sometimes produce hallucinations that they can separately recognize as incorrect. To do this, we c…

2023

Detoxifying Text with MaRCo: Controllable Revision with Experts and Anti-Experts

ACL 2023short

Text detoxification has the potential to mitigate the harms of toxicity by rephrasing text to remove offensive meaning, but subtle toxicity remains challenging to tackle. We introduce MaRCo, a detoxification algorithm that combines controllable generation and text rewriting methods using a Product o…

2023

Self-Instruct: Aligning Language Models with Self-Generated Instructions

ACL 2023long

Large “instruction-tuned” language models (i.e., finetuned to respond to instructions) have demonstrated a remarkable ability to generalize zero-shot to new tasks. Nevertheless, they depend heavily on human-written instruction data that is often limited in quantity, diversity, and creativity, theref…

2023

That was the last straw, we need more: Are Translation Systems Sensitive to Disambiguating Context?

EMNLP 2023long findings

The translation of ambiguous text presents a challenge for translation systems, as it requires using the surrounding context to disambiguate the intended meaning as much as possible. While prior work has studied ambiguities that result from different grammatical features of the source and target lan…

Cited by 0SourcecodeScholar
2023

We're Afraid Language Models Aren't Modeling Ambiguity

EMNLP 2023long main

Ambiguity is an intrinsic feature of natural language. Managing ambiguity is a key part of human language understanding, allowing us to anticipate misunderstanding as communicators and revise our interpretations as listeners. As language models are increasingly employed as dialogue interfaces and wr…

Cited by 0SourcecodeScholar
2022

Generated Knowledge Prompting for Commonsense Reasoning

ACL 2022long

It remains an open question whether incorporating external knowledge benefits commonsense reasoning while maintaining the flexibility of pretrained sequence models. To investigate this question, we develop generated knowledge prompting, which consists of generating knowledge from a language model, t…

2022

WANLI: Worker and AI Collaboration for Natural Language Inference Dataset Creation

EMNLP 2022finding

A recurring challenge of crowdsourcing NLP datasets at scale is that human writers often rely on repetitive patterns when crafting examples, leading to a lack of linguistic diversity. We introduce a novel approach for dataset creation based on worker and AI collaboration, which brings together the g…

2021

DExperts: Decoding-Time Controlled Text Generation with Experts and Anti-Experts

ACL 2021long

Despite recent advances in natural language generation, it remains challenging to control attributes of generated text. We propose DExperts: Decoding-time Experts, a decoding-time method for controlled text generation that combines a pretrained language model with “expert” LMs and/or “anti-expert” L…